diff --git a/.codecov.yml b/.codecov.yml
index 169e0d091..18782759f 100644
--- a/.codecov.yml
+++ b/.codecov.yml
@@ -11,11 +11,11 @@ coverage:
       default:
         threshold: 1%
         paths:
-          - "library"
+          - "src"
     patch:
       default:
         threshold: 3%
         paths:
-          - "library"
+          - "src"
 
 comment: false
diff --git a/.github/release-checklist.md b/.github/release-checklist.md
index 8def7d988..93e0d91ce 100644
--- a/.github/release-checklist.md
+++ b/.github/release-checklist.md
@@ -5,8 +5,8 @@ Template to use for release PRs from `develop` to `stable`
 
 PR for tracking changes for the x.x.x release. Target release date: **DOW MONTH DAY YEAR**.
 - [ ] Check if any dependencies need updating.
-- [ ] Check if the `cacert.pem` file needs updating.
-- [ ] Update the version constant in `library/Requests.php`.
+- [ ] Check if the `src/Transports/cacert.pem` file needs updating.
+- [ ] Update the version constant in `src/Requests.php`.
 - [ ] Add changelog for the release - PR #xxx
 - [ ] Merge this PR.
 - [ ] Make sure all CI builds are green.
diff --git a/.phpcs.xml.dist b/.phpcs.xml.dist
index bca2cd08f..68974d6a0 100644
--- a/.phpcs.xml.dist
+++ b/.phpcs.xml.dist
@@ -16,8 +16,8 @@
 	<file>.</file>
 
 	<!-- Third party files and build files don't need to comply with these coding standards. -->
-	<exclude-pattern>*/library/Requests/IRI\.php$</exclude-pattern>
-	<exclude-pattern>*/tests/IRITest\.php$</exclude-pattern>
+	<exclude-pattern>*/src/Iri\.php$</exclude-pattern>
+	<exclude-pattern>*/tests/IriTest\.php$</exclude-pattern>
 	<exclude-pattern>*/vendor/*</exclude-pattern>
 	<exclude-pattern>*/tests/coverage/</exclude-pattern>
 
@@ -186,11 +186,12 @@
 		<properties>
 			<property name="prefixes" type="array">
 				<element value="Requests"/>
+				<element value="WpOrg\Requests"/>
 			</property>
 		</properties>
 		
-		<!-- Only code within the actual distributed package needs to be prefixed. -->
-		<include-pattern>/library/*\.php$</include-pattern>
+		<exclude-pattern>*/examples/*\.php$</exclude-pattern>
+		<exclude-pattern>*/tests/bootstrap\.php$</exclude-pattern>
 	</rule>
 
 	<!-- Simplify alignment rules for multiline arrays. -->
@@ -219,8 +220,11 @@
 
 	<!-- Don't rename existing classes to prevent a BC break. -->
 	<rule ref="PEAR.NamingConventions.ValidClassName.Invalid">
-		<exclude-pattern>*/Transport/cURL\.php$</exclude-pattern>
-		<exclude-pattern>*/Transport/fsockopen\.php$</exclude-pattern>
+		<exclude-pattern>*/library/Deprecated\.php$</exclude-pattern>
+	</rule>
+
+	<rule ref="Generic.Files.OneObjectStructurePerFile.MultipleFound">
+		<exclude-pattern>*/library/Deprecated\.php$</exclude-pattern>
 	</rule>
 
 	<!-- ==========================================================================
diff --git a/README.md b/README.md
index 62f4c1a09..57257201e 100644
--- a/README.md
+++ b/README.md
@@ -24,7 +24,7 @@ We all have better things to do. That's why Requests was born.
 ```php
 $headers = array('Accept' => 'application/json');
 $options = array('auth' => array('user', 'pass'));
-$request = Requests::get('https://api.github.com/gists', $headers, $options);
+$request = WpOrg\Requests\Requests::get('https://api.github.com/gists', $headers, $options);
 
 var_dump($request->status_code);
 // int(200)
@@ -79,14 +79,14 @@ To install the source code:
 $ git clone git://github.com/WordPress/Requests.git
 ```
 
-And include it in your scripts:
+Next, include the autoloader in your scripts:
 ```php
-require_once '/path/to/Requests/library/Requests.php';
+require_once '/path/to/Requests/src/Autoload.php';
 ```
 
-You'll probably also want to register an autoloader:
+You'll probably also want to register the autoloader:
 ```php
-Requests::register_autoloader();
+WpOrg\Requests\Autoload::register();
 ```
 
 ### Install source from zip/tarball
@@ -104,13 +104,15 @@ $ wget https://github.com/WordPress/Requests/tarball/stable -O - | tar xzv
 
 ### Using a Class Loader
 If you're using a class loader (e.g., [Symfony Class Loader][]) for
-[PSR-0][]-style class loading:
+[PSR-4][]-style class loading:
 ```php
-$loader->registerPrefix('Requests', 'path/to/vendor/Requests/library');
+$loader = new Psr4ClassLoader();
+$loader->addPrefix('WpOrg\\Requests\\', 'path/to/vendor/Requests/src');
+$loader->register();
 ```
 
 [Symfony Class Loader]: https://github.com/symfony/ClassLoader
-[PSR-0]: https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-0.md
+[PSR-4]: https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-4.md
 
 
 Documentation
@@ -119,7 +121,7 @@ The best place to start is our [prose-based documentation][], which will guide
 you through using Requests.
 
 After that, take a look at [the documentation for
-`Requests::request()`][request_method], where all the parameters are fully
+`\WpOrg\Requests\Requests::request()`][request_method], where all the parameters are fully
 documented.
 
 Requests is [100% documented with PHPDoc](https://requests.ryanmccue.info/api/).
diff --git a/composer.json b/composer.json
index 614a3337d..48301f5b2 100644
--- a/composer.json
+++ b/composer.json
@@ -51,13 +51,14 @@
   },
   "type": "library",
   "autoload": {
-    "psr-0": {
-      "Requests": "library/"
-    }
+    "psr-4": {
+      "WpOrg\\Requests\\": "src/"
+    },
+    "classmap": ["library/Deprecated.php", "library/Requests.php"]
   },
   "autoload-dev": {
     "psr-4": {
-      "Requests\\Tests\\": "tests/"
+      "WpOrg\\Requests\\Tests\\": "tests/"
     }
   },
   "scripts": {
diff --git a/docs/README.md b/docs/README.md
index f1a98344e..65975c52a 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -17,6 +17,7 @@ here are prose; you might also want to check out the [API documentation][].
 	* [Custom authentication][authentication-custom]
 	* [Requests through proxy][proxy]
 	* [Hooking system][hooks]
+* [Upgrading to Requests 2.0][upgrading]
 
 [goals]: goals.md
 [why-requests]: why-requests.md
@@ -26,3 +27,4 @@ here are prose; you might also want to check out the [API documentation][].
 [authentication-custom]: authentication-custom.md
 [hooks]: hooks.md
 [proxy]: proxy.md
+[upgrading]: upgrading.md
diff --git a/docs/authentication-custom.md b/docs/authentication-custom.md
index e4f55854a..07d4e3831 100644
--- a/docs/authentication-custom.md
+++ b/docs/authentication-custom.md
@@ -1,7 +1,7 @@
 Custom Authentication
 =====================
 Custom authentication handlers are designed to be straight-forward to write.
-In order to write a handler, you'll need to implement the `Requests_Auth`
+In order to write a handler, you'll need to implement the `WpOrg\Requests\Auth`
 interface.
 
 An instance of this handler can then be passed to Requests via the `auth`
@@ -12,14 +12,14 @@ authenticates the call if said header is set to `Yummy`. (I don't know of any
 services that do this; perhaps this is a market waiting to be tapped?)
 
 ```php
-class MySoftware_Auth_Hotdog implements Requests_Auth {
+class MySoftware_Auth_Hotdog implements WpOrg\Requests\Auth {
     protected $password;
 
     public function __construct($password) {
         $this->password = $password;
     }
 
-    public function register(Requests_Hooks &$hooks) {
+    public function register(WpOrg\Requests\Hooks &$hooks) {
         $hooks->register('requests.before_request', array($this, 'before_request'));
     }
 
@@ -35,7 +35,7 @@ We then use this in our request calls like this:
 $options = array(
     'auth' => new MySoftware_Auth_Hotdog('yummy')
 );
-$response = Requests::get('http://hotdogbin.org/admin', array(), $options);
+$response = WpOrg\Requests\Requests::get('http://hotdogbin.org/admin', array(), $options);
 ```
 
 For more information on how to register and use hooks, see the [hooking
diff --git a/docs/authentication.md b/docs/authentication.md
index fd49391ef..b394002b1 100644
--- a/docs/authentication.md
+++ b/docs/authentication.md
@@ -8,9 +8,9 @@ A Basic authenticated call can be made like this:
 
 ```php
 $options = array(
-    'auth' => new Requests_Auth_Basic(array('user', 'password'))
+    'auth' => new WpOrg\Requests\Auth\Basic(array('user', 'password'))
 );
-Requests::get('https://httpbin.org/basic-auth/user/password', array(), $options);
+WpOrg\Requests\Requests::get('https://httpbin.org/basic-auth/user/password', array(), $options);
 ```
 
 As Basic authentication is usually what you want when you specify a username
@@ -20,14 +20,14 @@ and password, you can also just pass in an array as a shorthand:
 $options = array(
     'auth' => array('user', 'password')
 );
-Requests::get('https://httpbin.org/basic-auth/user/password', array(), $options);
+WpOrg\Requests\Requests::get('https://httpbin.org/basic-auth/user/password', array(), $options);
 ```
 
 Note that `POST`/`PUT` requests take a `$data` parameter, so you need to pass that
 before `$options`:
 
 ```php
-Requests::post('https://httpbin.org/basic-auth/user/password', array(), null, $options);
+WpOrg\Requests\Requests::post('https://httpbin.org/basic-auth/user/password', array(), null, $options);
 ```
 
 ***
diff --git a/docs/hooks.md b/docs/hooks.md
index 8772a0bfe..70585aa5e 100644
--- a/docs/hooks.md
+++ b/docs/hooks.md
@@ -3,7 +3,7 @@ Hooks
 Requests has a hook system that you can use to manipulate parts of the request
 process along with internal transport hooks.
 
-Check out the [API documentation for `Requests_Hooks`][requests_hooks] for more
+Check out the [API documentation for `WpOrg\Requests\Hooks`][requests_hooks] for more
 information on how to use the hook system.
 
 [requests_hooks]: {{ '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/api/class-Requests_Hooks.html' | prepend: site.baseurl }}
@@ -28,7 +28,7 @@ Available Hooks
 
     Alter the response object before it is returned to the user.
 
-    Parameters: `Requests_Response &$return`
+    Parameters: `WpOrg\Requests\Response &$return`
 
 * **`curl.before_request`**
 
@@ -88,16 +88,18 @@ Authentication guide][authentication-custom] instead.
 
 [authentication-custom]: authentication-custom.md
 
-In order to register your own hooks, you need to instantiate `Requests_Hooks`
+In order to register your own hooks, you need to instantiate `WpOrg\Requests\Hooks`
 and pass the object in via the `'hooks'` option.
 
 ```php
-$hooks = new Requests_Hooks();
+$hooks = new WpOrg\Requests\Hooks();
 $hooks->register('requests.after_request', 'mycallback');
 
-$request = Requests::get('https://httpbin.org/get', array(), array('hooks' => $hooks));
+$request = WpOrg\Requests\Requests::get('https://httpbin.org/get', array(), array('hooks' => $hooks));
 ```
 
 ***
 
 Previous: [Requests through proxy](proxy.md)
+
+Next: [Upgrading to Requests 2.0](upgrading.md)
diff --git a/docs/proxy.md b/docs/proxy.md
index 31e2a725c..4459c4a19 100644
--- a/docs/proxy.md
+++ b/docs/proxy.md
@@ -9,7 +9,7 @@ To make requests through an open proxy, specify the following options:
 $options = array(
     'proxy' => '127.0.0.1:3128'
 );
-Requests::get('https://httpbin.org/ip', array(), $options);
+WpOrg\Requests\Requests::get('https://httpbin.org/ip', array(), $options);
 ```
 
 If your proxy needs you to authenticate, the option will become an array like
@@ -19,7 +19,7 @@ in the following example:
 $options = array(
     'proxy' => array( '127.0.0.1:3128', 'my_username', 'my_password' )
 );
-Requests::get('https://httpbin.org/ip', array(), $options);
+WpOrg\Requests\Requests::get('https://httpbin.org/ip', array(), $options);
 ```
 
 ***
diff --git a/docs/upgrading.md b/docs/upgrading.md
new file mode 100644
index 000000000..8361fb72e
--- /dev/null
+++ b/docs/upgrading.md
@@ -0,0 +1,110 @@
+Upgrading to Requests 2.0
+=========================
+
+Autoloading the Requests library
+--------------------------------
+
+In Requests 1.x, both a custom autoloader native to Requests, as well as autoloading
+via the Composer `vendor/autoload.php` file was supported.
+
+The same applies to Requests 2.x, though the way to initiate the Requests native
+custom autoloader has changed.
+
+If you were autoloading the Requests library via the Composer autoload file,
+no changes are needed.
+
+```php
+// OLD: Using the custom autoloader in Requests 1.x.
+require_once 'path/to/Requests/library/Requests.php';
+Requests::register_autoloader();
+
+// NEW: Using the custom autoloader in Requests 2.x.
+require_once 'path/to/Requests/src/Autoload.php';
+WpOrg\Requests\Autoload::register();
+```
+
+For backward compatibility reasons, the Requests 1.x manner to call the autoloader
+will still be supported for the time being, but it is recommended to update
+your code to use the new autoloader.
+
+
+New namespaced names
+--------------------
+
+As of Requests 2.0.0, all code in the Requests library is namespaced and
+class/interface names have been normalized to CamelCaps.
+
+We recommend for all users to upgrade their code to use the new namespaced
+class names.
+
+| Type      | Request 1.x name                             | Requests >= 2.0 name                                                    |
+|-----------|----------------------------------------------|-------------------------------------------------------------------------|
+| class     | `Requests`                                   | `WpOrg\Requests\Requests` <strong><sup>1</sup></strong>                 |
+| interface | `Requests_Auth`                              | `WpOrg\Requests\Auth`                                                   |
+| interface | `Requests_Hooker`                            | `WpOrg\Requests\Hooker`                                                 |
+| interface | `Requests_Transport`                         | `WpOrg\Requests\Transport`                                              |
+| interface | `Requests_Proxy`                             | `WpOrg\Requests\Proxy`                                                  |
+| class     | `Requests_Cookie`                            | `WpOrg\Requests\Cookie`                                                 |
+| class     | `Requests_Exception`                         | `WpOrg\Requests\Exception`                                              |
+| class     | `Requests_Hooks`                             | `WpOrg\Requests\Hooks`                                                  |
+| class     | `Requests_IDNAEncoder`                       | `WpOrg\Requests\IdnaEncoder`                                            |
+| class     | `Requests_IPv6`                              | `WpOrg\Requests\Ipv6`                                                   |
+| class     | `Requests_IRI`                               | `WpOrg\Requests\Iri`                                                    |
+| class     | `Requests_Response`                          | `WpOrg\Requests\Response`                                               |
+| class     | `Requests_Session`                           | `WpOrg\Requests\Session`                                                |
+| class     | `Requests_SSL`                               | `WpOrg\Requests\Ssl`                                                    |
+| class     | `Requests_Auth_Basic`                        | `WpOrg\Requests\Auth\Basic`                                             |
+| class     | `Requests_Cookie_Jar`                        | `WpOrg\Requests\Cookie\Jar`                                             |
+| class     | `Requests_Proxy_HTTP`                        | `WpOrg\Requests\Proxy\Http`                                             |
+| class     | `Requests_Response_Headers`                  | `WpOrg\Requests\Response\Headers`                                       |
+| class     | `Requests_Transport_cURL`                    | `WpOrg\Requests\Transport\Curl`                                         |
+| class     | `Requests_Transport_fsockopen`               | `WpOrg\Requests\Transport\Fsockopen`                                    |
+| class     | `Requests_Utility_CaseInsensitiveDictionary` | `WpOrg\Requests\Utility\CaseInsensitiveDictionary`                      |
+| class     | `Requests_Utility_FilteredIterator`          | `WpOrg\Requests\Utility\FilteredIterator`                               |
+| class     | `Requests_Exception_HTTP`                    | `WpOrg\Requests\Exception\Http`                                         |
+| class     | `Requests_Exception_Transport`               | `WpOrg\Requests\Exception\Transport`                                    |
+| class     | `Requests_Exception_Transport_cURL`          | `WpOrg\Requests\Exception\Transport\Curl`                               |
+| class     | `Requests_Exception_HTTP_###`                | `WpOrg\Requests\Exception\Http\Status###` <strong><sup>2</sup></strong> |
+| class     | `Requests_Exception_HTTP_Unknown`            | `WpOrg\Requests\Exception\Http\StatusUnknown`                           |
+
+
+**Notes**:
+
+<sup>1</sup> The original `Requests` class has been split into two classes:
+* `WpOrg\Requests\Requests` contains the actual functionality;
+* `WpOrg\Requests\Autoload` contains the custom autoloader.
+* The original non-namespaced `Requests` class remains for backward-compatibility
+    reasons and extends `WpOrg\Requests\Requests` and uses `WpOrg\Requests\Autoload`
+    in the old autoload functions, `Requests::autoloader()` and
+    `Requests::register_autoloader()`.
+
+<sup>2</sup> The `###` in the HTTP Exception classes represents a three character,
+numeric HTTP status code.
+Exception classes are available for HTTP status 304 - 306, 400 - 418,
+428, 429, 431, 500 - 505 and 511.
+
+
+Backward compatibility layer
+----------------------------
+
+If for some reason, you can not yet upgrade or have to support both Requests 1.x
+as well as Requests >= 2.0, a backward compatibility layer is provided.
+This backward compatibility layer will work with both the Requests native
+custom autoloader, as well as when using the Composer `vendor/autoload.php` file.
+
+Using the old PSR-0 names will still work, but a deprecation notice will be
+thrown the first time during a page load when a PSR-0 class name is referenced.
+
+For the lifetime of Requests 2.x, the deprecation notices can be disabled by
+defining a global `REQUESTS_SILENCE_PSR0_DEPRECATIONS` constant and
+setting the value of this constant to `true`.
+The constant needs to be defined before the first PSR-0 class name is requested.
+
+As of Requests 3.0, support for the constant will be removed and
+the deprecation notice will always be thrown.
+
+As of Requests 4.0, the backward compatibility layer will be removed.
+
+***
+
+Previous: [Hooks](hooks.md)
diff --git a/docs/usage-advanced.md b/docs/usage-advanced.md
index 114a3fa90..0f0319535 100644
--- a/docs/usage-advanced.md
+++ b/docs/usage-advanced.md
@@ -10,16 +10,16 @@ default parameters for these.
 Let's simulate communicating with GitHub.
 
 ```php
-$session = new Requests_Session('https://api.github.com/');
+$session = new WpOrg\Requests\Session('https://api.github.com/');
 $session->headers['X-ContactAuthor'] = 'rmccue';
 $session->useragent = 'My-Awesome-App';
 
 $response = $session->get('/zen');
 ```
 
-You can use the `url`, `headers`, `data` and `options` properties of the Session
+You can use the `url`, `headers`, `data` and `options` properties of the `WpOrg\Requests\Session`
 object to set the defaults for this session, and the constructor also takes
-parameters in the same order as `Requests::request()`. Accessing any other
+parameters in the same order as `WpOrg\Requests\Requests::request()`. Accessing any other
 properties will set the corresponding key in the options array; that is:
 
 ```php
@@ -36,7 +36,7 @@ Secure Requests with SSL
 By default, HTTPS requests will use the most secure options available:
 
 ```php
-$response = Requests::get('https://httpbin.org/');
+$response = WpOrg\Requests\Requests::get('https://httpbin.org/');
 ```
 
 Requests bundles certificates from the [Mozilla certificate authority list][],
@@ -49,7 +49,7 @@ accepted by cURL and OpenSSL):
 $options = array(
     'verify' => '/path/to/cacert.pem'
 );
-$response = Requests::get('https://httpbin.org/', array(), $options);
+$response = WpOrg\Requests\Requests::get('https://httpbin.org/', array(), $options);
 ```
 
 Alternatively, if you want to disable verification completely, this is possible
diff --git a/docs/usage.md b/docs/usage.md
index 95534005f..f1e0074b7 100644
--- a/docs/usage.md
+++ b/docs/usage.md
@@ -15,10 +15,10 @@ One of the most basic things you can do with HTTP is make a GET request.
 Let's grab GitHub's public events:
 
 ```php
-$response = Requests::get('https://api.github.com/events');
+$response = WpOrg\Requests\Requests::get('https://api.github.com/events');
 ```
 
-`$response` is now a **Requests_Response** object. Response objects are what
+`$response` is now a **WpOrg\Requests\Response** object. Response objects are what
 you'll be working with whenever you want to get data back from your request.
 
 
@@ -38,7 +38,7 @@ If you want to add custom headers to the request, simply pass them in as an
 associative array as the second parameter:
 
 ```php
-$response = Requests::get('https://api.github.com/events', array('X-Requests' => 'Is Awesome!'));
+$response = WpOrg\Requests\Requests::get('https://api.github.com/events', array('X-Requests' => 'Is Awesome!'));
 ```
 
 
@@ -47,7 +47,7 @@ Make a POST Request
 Making a POST request is very similar to making a GET:
 
 ```php
-$response = Requests::post('https://httpbin.org/post');
+$response = WpOrg\Requests\Requests::post('https://httpbin.org/post');
 ```
 
 You'll probably also want to pass in some data. You can pass in either a
@@ -58,7 +58,7 @@ internally) as the third parameter (after the URL and headers):
 
 ```php
 $data = array('key1' => 'value1', 'key2' => 'value2');
-$response = Requests::post('https://httpbin.org/post', array(), $data);
+$response = WpOrg\Requests\Requests::post('https://httpbin.org/post', array(), $data);
 var_dump($response->body);
 ```
 
@@ -93,7 +93,7 @@ sending it:
 $url = 'https://api.github.com/some/endpoint';
 $headers = array('Content-Type' => 'application/json');
 $data = array('some' => 'data');
-$response = Requests::post($url, $headers, json_encode($data));
+$response = WpOrg\Requests\Requests::post($url, $headers, json_encode($data));
 ```
 
 Note that if you don't manually specify a Content-Type header, Requests has
diff --git a/docs/why-requests.md b/docs/why-requests.md
index 66fcc5c70..ca1253e11 100644
--- a/docs/why-requests.md
+++ b/docs/why-requests.md
@@ -60,7 +60,7 @@ Why should I use Requests?
 
 [codecov]: https://app.codecov.io/gh/WordPress/Requests/branch/stable
 [hooking system]: hooks.md
-[requests_ssl]: https://github.com/WordPress/Requests/blob/stable/library/Requests/SSL.php
+[requests_ssl]: https://github.com/WordPress/Requests/blob/stable/src/Ssl.php
 [ghactions]: https://github.com/WordPress/Requests/actions
 [wpssl]: https://core.trac.wordpress.org/ticket/25007
 
@@ -89,8 +89,8 @@ instead of something else, in our opinion.
 
    Requests, on the other hand, exposes only a handful of classes to the
    global namespace, most of which are for internal use. You can learn to use
-   the `Requests::request()` method and the `Requests_Response` object in the
-   space of 10 minutes and you already know how to use Requests.
+   the `WpOrg\Requests\Requests::request()` method and the `WpOrg\Requests\Response`
+   object in the space of 10 minutes and you already know how to use Requests.
 
 
 ### Guzzle
@@ -162,7 +162,7 @@ instead of something else, in our opinion.
    using PEAR for your project.
 
    Requests is entirely self-contained, and includes all the libraries it needs
-   (for example, `Requests_IRI` is based on `ComplexPie_IRI` by Geoffrey Sneddon).
+   (for example, `WpOrg\Requests\Iri` is based on `ComplexPie_IRI` by Geoffrey Sneddon).
 
 
 ### Zend Framework's Zend\_Http\_Client
diff --git a/examples/basic-auth.php b/examples/basic-auth.php
index dfabb399f..f512454f5 100644
--- a/examples/basic-auth.php
+++ b/examples/basic-auth.php
@@ -1,16 +1,16 @@
 <?php
 
-// First, include Requests
-require_once dirname(__DIR__) . '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/library/Requests.php';
+// First, include the Requests Autoloader.
+require_once dirname(__DIR__) . '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/src/Autoload.php';
 
-// Next, make sure Requests can load internal classes
-Requests::register_autoloader();
+// Next, make sure Requests can load internal classes.
+WpOrg\Requests\Autoload::register();
 
 // Now let's make a request!
 $options = array(
 	'auth' => array('someuser', 'password'),
 );
-$request = Requests::get('http://httpbin.org/basic-auth/someuser/password', array(), $options);
+$request = WpOrg\Requests\Requests::get('http://httpbin.org/basic-auth/someuser/password', array(), $options);
 
 // Check what we received
 var_dump($request);
diff --git a/examples/cookie.php b/examples/cookie.php
index d00e79911..943f6d6eb 100644
--- a/examples/cookie.php
+++ b/examples/cookie.php
@@ -1,16 +1,16 @@
 <?php
 
-// First, include Requests
-require_once dirname(__DIR__) . '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/library/Requests.php';
+// First, include the Requests Autoloader.
+require_once dirname(__DIR__) . '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/src/Autoload.php';
 
-// Next, make sure Requests can load internal classes
-Requests::register_autoloader();
+// Next, make sure Requests can load internal classes.
+WpOrg\Requests\Autoload::register();
 
 // Say you need to fake a login cookie
-$c = new Requests_Cookie('login_uid', 'something');
+$c = new WpOrg\Requests\Cookie('login_uid', 'something');
 
 // Now let's make a request!
-$request = Requests::get('http://httpbin.org/cookies', array('Cookie' => $c->format_for_header()));
+$request = WpOrg\Requests\Requests::get('http://httpbin.org/cookies', array('Cookie' => $c->format_for_header()));
 
 // Check what we received
 var_dump($request);
diff --git a/examples/cookie_jar.php b/examples/cookie_jar.php
index 21e8445bc..546d8f275 100644
--- a/examples/cookie_jar.php
+++ b/examples/cookie_jar.php
@@ -1,16 +1,16 @@
 <?php
 
-// First, include Requests
-require_once dirname(__DIR__) . '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/library/Requests.php';
+// First, include the Requests Autoloader.
+require_once dirname(__DIR__) . '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/src/Autoload.php';
 
-// Next, make sure Requests can load internal classes
-Requests::register_autoloader();
+// Next, make sure Requests can load internal classes.
+WpOrg\Requests\Autoload::register();
 
 // Say you need to fake a login cookie
-$c = new Requests_Cookie_Jar(['login_uid' => 'something']);
+$c = new WpOrg\Requests\Cookie\Jar(['login_uid' => 'something']);
 
 // Now let's make a request!
-$request = Requests::get(
+$request = WpOrg\Requests\Requests::get(
 	'http://httpbin.org/cookies', // Url
 	[],  // No need to set the headers the Jar does this for us
 	['cookies' => $c] // Pass in the Jar as an option
diff --git a/examples/get.php b/examples/get.php
index 953bf1694..f96d075cb 100644
--- a/examples/get.php
+++ b/examples/get.php
@@ -1,13 +1,13 @@
 <?php
 
-// First, include Requests
-require_once dirname(__DIR__) . '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/library/Requests.php';
+// First, include the Requests Autoloader.
+require_once dirname(__DIR__) . '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/src/Autoload.php';
 
-// Next, make sure Requests can load internal classes
-Requests::register_autoloader();
+// Next, make sure Requests can load internal classes.
+WpOrg\Requests\Autoload::register();
 
 // Now let's make a request!
-$request = Requests::get('http://httpbin.org/get', array('Accept' => 'application/json'));
+$request = WpOrg\Requests\Requests::get('http://httpbin.org/get', array('Accept' => 'application/json'));
 
 // Check what we received
 var_dump($request);
diff --git a/examples/multiple.php b/examples/multiple.php
index 0de0d8f93..7bdab33f1 100644
--- a/examples/multiple.php
+++ b/examples/multiple.php
@@ -1,10 +1,10 @@
 <?php
 
-// First, include Requests
-require_once dirname(__DIR__) . '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/library/Requests.php';
+// First, include the Requests Autoloader.
+require_once dirname(__DIR__) . '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/src/Autoload.php';
 
-// Next, make sure Requests can load internal classes
-Requests::register_autoloader();
+// Next, make sure Requests can load internal classes.
+WpOrg\Requests\Autoload::register();
 
 // Setup what we want to request
 $requests = array(
@@ -35,7 +35,7 @@ function my_callback(&$request, $id) {
 );
 
 // Send the request!
-$responses = Requests::request_multiple($requests, $options);
+$responses = WpOrg\Requests\Requests::request_multiple($requests, $options);
 
 // Note: the response from the above call will be an associative array matching
 // $requests with the response data, however we've already handled it in
diff --git a/examples/post.php b/examples/post.php
index f1422db7a..47abd674d 100644
--- a/examples/post.php
+++ b/examples/post.php
@@ -1,13 +1,13 @@
 <?php
 
-// First, include Requests
-require_once dirname(__DIR__) . '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/library/Requests.php';
+// First, include the Requests Autoloader.
+require_once dirname(__DIR__) . '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/src/Autoload.php';
 
-// Next, make sure Requests can load internal classes
-Requests::register_autoloader();
+// Next, make sure Requests can load internal classes.
+WpOrg\Requests\Autoload::register();
 
 // Now let's make a request!
-$request = Requests::post('http://httpbin.org/post', array(), array('mydata' => 'something'));
+$request = WpOrg\Requests\Requests::post('http://httpbin.org/post', array(), array('mydata' => 'something'));
 
 // Check what we received
 var_dump($request);
diff --git a/examples/proxy.php b/examples/proxy.php
index a9037eebd..226e29854 100644
--- a/examples/proxy.php
+++ b/examples/proxy.php
@@ -1,10 +1,10 @@
 <?php
 
-// First, include Requests
-require_once dirname(__DIR__) . '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/library/Requests.php';
+// First, include the Requests Autoloader.
+require_once dirname(__DIR__) . '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/src/Autoload.php';
 
-// Next, make sure Requests can load internal classes
-Requests::register_autoloader();
+// Next, make sure Requests can load internal classes.
+WpOrg\Requests\Autoload::register();
 
 // Now let's make a request via a proxy.
 $options = array(
@@ -12,7 +12,7 @@
 	// If you need to authenticate, use the following syntax:
 	// 'proxy' => array( '127.0.0.1:8080', 'username', 'password' ),
 );
-$request = Requests::get('http://httpbin.org/ip', array(), $options);
+$request = WpOrg\Requests\Requests::get('http://httpbin.org/ip', array(), $options);
 
 // See result
 var_dump($request->body);
diff --git a/examples/session.php b/examples/session.php
index e8e9f2173..600afdbac 100644
--- a/examples/session.php
+++ b/examples/session.php
@@ -1,13 +1,13 @@
 <?php
 
-// First, include Requests
-require_once dirname(__DIR__) . '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/library/Requests.php';
+// First, include the Requests Autoloader.
+require_once dirname(__DIR__) . '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/src/Autoload.php';
 
-// Next, make sure Requests can load internal classes
-Requests::register_autoloader();
+// Next, make sure Requests can load internal classes.
+WpOrg\Requests\Autoload::register();
 
 // Set up our session
-$session                    = new Requests_Session('http://httpbin.org/');
+$session                    = new WpOrg\Requests\Session('http://httpbin.org/');
 $session->headers['Accept'] = 'application/json';
 $session->useragent         = 'Awesomesauce';
 
diff --git a/examples/timeout.php b/examples/timeout.php
index 5743747b6..91d963353 100644
--- a/examples/timeout.php
+++ b/examples/timeout.php
@@ -1,10 +1,10 @@
 <?php
 
-// First, include Requests
-require_once dirname(__DIR__) . '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/library/Requests.php';
+// First, include the Requests Autoloader.
+require_once dirname(__DIR__) . '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/src/Autoload.php';
 
-// Next, make sure Requests can load internal classes
-Requests::register_autoloader();
+// Next, make sure Requests can load internal classes.
+WpOrg\Requests\Autoload::register();
 
 // Define a timeout of 2.5 seconds
 $options = array(
@@ -12,6 +12,6 @@
 );
 
 // Now let's make a request to a page that will delay its response by 3 seconds
-$request = Requests::get('http://httpbin.org/delay/3', array(), $options);
+$request = WpOrg\Requests\Requests::get('http://httpbin.org/delay/3', array(), $options);
 
 // An exception will be thrown, stating a timeout of the request !
diff --git a/library/Deprecated.php b/library/Deprecated.php
new file mode 100644
index 000000000..39e947aa0
--- /dev/null
+++ b/library/Deprecated.php
@@ -0,0 +1,208 @@
+<?php
+/**
+ * Backwards compatibility layer for Requests.
+ *
+ * Allows for Composer to autoload the old PSR-0 class names based on a classmap.
+ *
+ * All classes in this file are deprecated.
+ * Please see the Changelog for the 2.0.0 release for upgrade notes.
+ *
+ * @package Requests
+ *
+ * @deprecated 2.0.0 Use the PSR-4 class names instead.
+ */
+
+/*
+ * Integrators who cannot yet upgrade to the PSR-4 class names can silence deprecations
+ * by defining a `REQUESTS_SILENCE_PSR0_DEPRECATIONS` constant and setting it to `true`.
+ * The constant needs to be defined before the first deprecated class is requested
+ * via this Composer autoload file.
+ */
+if (!defined('REQUESTS_SILENCE_PSR0_DEPRECATIONS') || REQUESTS_SILENCE_PSR0_DEPRECATIONS !== true) {
+	// phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_trigger_error
+	trigger_error(
+		'The PSR-0 `Requests_...` class names in the Request library are deprecated.'
+		. ' Switch to the PSR-4 `WpOrg\Requests\...` class names at your earliest convenience.',
+		E_USER_DEPRECATED
+	);
+
+	// Prevent the deprecation notice from being thrown twice.
+	if (!defined('REQUESTS_SILENCE_PSR0_DEPRECATIONS')) {
+		define('REQUESTS_SILENCE_PSR0_DEPRECATIONS', true);
+	}
+}
+
+if (interface_exists('Requests_Auth') === false && interface_exists('WpOrg\Requests\Auth') === true) {
+	interface Requests_Auth extends WpOrg\Requests\Auth {}
+}
+if (interface_exists('Requests_Hooker') === false && interface_exists('WpOrg\Requests\Hooker') === true) {
+	interface Requests_Hooker extends WpOrg\Requests\Hooker {}
+}
+if (interface_exists('Requests_Proxy') === false && interface_exists('WpOrg\Requests\Proxy') === true) {
+	interface Requests_Proxy extends WpOrg\Requests\Proxy {}
+}
+if (interface_exists('Requests_Transport') === false && interface_exists('WpOrg\Requests\Transport') === true) {
+	interface Requests_Transport extends WpOrg\Requests\Transport {}
+}
+
+if (class_exists('Requests_Cookie') === false && class_exists('WpOrg\Requests\Cookie') === true) {
+	class Requests_Cookie extends WpOrg\Requests\Cookie {}
+}
+if (class_exists('Requests_Exception') === false && class_exists('WpOrg\Requests\Exception') === true) {
+	class Requests_Exception extends WpOrg\Requests\Exception {}
+}
+if (class_exists('Requests_Hooks') === false && class_exists('WpOrg\Requests\Hooks') === true) {
+	class Requests_Hooks extends WpOrg\Requests\Hooks {}
+}
+if (class_exists('Requests_IDNAEncoder') === false && class_exists('WpOrg\Requests\IdnaEncoder') === true) {
+	class Requests_IDNAEncoder extends WpOrg\Requests\IdnaEncoder {}
+}
+if (class_exists('Requests_IPv6') === false && class_exists('WpOrg\Requests\Ipv6') === true) {
+	class Requests_IPv6 extends WpOrg\Requests\Ipv6 {}
+}
+if (class_exists('Requests_IRI') === false && class_exists('WpOrg\Requests\Iri') === true) {
+	class Requests_IRI extends WpOrg\Requests\Iri {}
+}
+if (class_exists('Requests_Response') === false && class_exists('WpOrg\Requests\Response') === true) {
+	class Requests_Response extends WpOrg\Requests\Response {}
+}
+if (class_exists('Requests_Session') === false && class_exists('WpOrg\Requests\Session') === true) {
+	class Requests_Session extends WpOrg\Requests\Session {}
+}
+if (class_exists('Requests_SSL') === false && class_exists('WpOrg\Requests\Ssl') === true) {
+	class Requests_SSL extends WpOrg\Requests\Ssl {}
+}
+
+if (class_exists('Requests_Auth_Basic') === false && class_exists('WpOrg\Requests\Auth\Basic') === true) {
+	class Requests_Auth_Basic extends WpOrg\Requests\Auth\Basic {}
+}
+if (class_exists('Requests_Cookie_Jar') === false && class_exists('WpOrg\Requests\Cookie\Jar') === true) {
+	class Requests_Cookie_Jar extends WpOrg\Requests\Cookie\Jar {}
+}
+if (class_exists('Requests_Proxy_HTTP') === false && class_exists('WpOrg\Requests\Proxy\Http') === true) {
+	class Requests_Proxy_HTTP extends WpOrg\Requests\Proxy\Http {}
+}
+if (class_exists('Requests_Response_Headers') === false && class_exists('WpOrg\Requests\Response\Headers') === true) {
+	class Requests_Response_Headers extends WpOrg\Requests\Response\Headers {}
+}
+if (class_exists('Requests_Transport_cURL') === false && class_exists('WpOrg\Requests\Transport\Curl') === true) {
+	class Requests_Transport_cURL extends WpOrg\Requests\Transport\Curl {}
+}
+if (class_exists('Requests_Transport_fsockopen') === false && class_exists('WpOrg\Requests\Transport\Fsockopen') === true) {
+	class Requests_Transport_fsockopen extends WpOrg\Requests\Transport\Fsockopen {}
+}
+if (class_exists('Requests_Utility_CaseInsensitiveDictionary') === false && class_exists('WpOrg\Requests\Utility\CaseInsensitiveDictionary') === true) {
+	class Requests_Utility_CaseInsensitiveDictionary extends WpOrg\Requests\Utility\CaseInsensitiveDictionary {}
+}
+if (class_exists('Requests_Utility_FilteredIterator') === false && class_exists('WpOrg\Requests\Utility\FilteredIterator') === true) {
+	class Requests_Utility_FilteredIterator extends WpOrg\Requests\Utility\FilteredIterator {}
+}
+
+if (class_exists('Requests_Exception_HTTP') === false && class_exists('WpOrg\Requests\Exception\Http') === true) {
+	class Requests_Exception_HTTP extends WpOrg\Requests\Exception\Http {}
+}
+if (class_exists('Requests_Exception_Transport') === false && class_exists('WpOrg\Requests\Exception\Transport') === true) {
+	class Requests_Exception_Transport extends WpOrg\Requests\Exception\Transport {}
+}
+if (class_exists('Requests_Exception_Transport_cURL') === false && class_exists('WpOrg\Requests\Exception\Transport\Curl') === true) {
+	class Requests_Exception_Transport_cURL extends WpOrg\Requests\Exception\Transport\Curl {}
+}
+if (class_exists('Requests_Exception_HTTP_304') === false && class_exists('WpOrg\Requests\Exception\Http\Status304') === true) {
+	class Requests_Exception_HTTP_304 extends WpOrg\Requests\Exception\Http\Status304 {}
+}
+if (class_exists('Requests_Exception_HTTP_305') === false && class_exists('WpOrg\Requests\Exception\Http\Status305') === true) {
+	class Requests_Exception_HTTP_305 extends WpOrg\Requests\Exception\Http\Status305 {}
+}
+if (class_exists('Requests_Exception_HTTP_306') === false && class_exists('WpOrg\Requests\Exception\Http\Status306') === true) {
+	class Requests_Exception_HTTP_306 extends WpOrg\Requests\Exception\Http\Status306 {}
+}
+if (class_exists('Requests_Exception_HTTP_400') === false && class_exists('WpOrg\Requests\Exception\Http\Status400') === true) {
+	class Requests_Exception_HTTP_400 extends WpOrg\Requests\Exception\Http\Status400 {}
+}
+if (class_exists('Requests_Exception_HTTP_401') === false && class_exists('WpOrg\Requests\Exception\Http\Status401') === true) {
+	class Requests_Exception_HTTP_401 extends WpOrg\Requests\Exception\Http\Status401 {}
+}
+if (class_exists('Requests_Exception_HTTP_402') === false && class_exists('WpOrg\Requests\Exception\Http\Status402') === true) {
+	class Requests_Exception_HTTP_402 extends WpOrg\Requests\Exception\Http\Status402 {}
+}
+if (class_exists('Requests_Exception_HTTP_403') === false && class_exists('WpOrg\Requests\Exception\Http\Status403') === true) {
+	class Requests_Exception_HTTP_403 extends WpOrg\Requests\Exception\Http\Status403 {}
+}
+if (class_exists('Requests_Exception_HTTP_404') === false && class_exists('WpOrg\Requests\Exception\Http\Status404') === true) {
+	class Requests_Exception_HTTP_404 extends WpOrg\Requests\Exception\Http\Status404 {}
+}
+if (class_exists('Requests_Exception_HTTP_405') === false && class_exists('WpOrg\Requests\Exception\Http\Status405') === true) {
+	class Requests_Exception_HTTP_405 extends WpOrg\Requests\Exception\Http\Status405 {}
+}
+if (class_exists('Requests_Exception_HTTP_406') === false && class_exists('WpOrg\Requests\Exception\Http\Status406') === true) {
+	class Requests_Exception_HTTP_406 extends WpOrg\Requests\Exception\Http\Status406 {}
+}
+if (class_exists('Requests_Exception_HTTP_407') === false && class_exists('WpOrg\Requests\Exception\Http\Status407') === true) {
+	class Requests_Exception_HTTP_407 extends WpOrg\Requests\Exception\Http\Status407 {}
+}
+if (class_exists('Requests_Exception_HTTP_408') === false && class_exists('WpOrg\Requests\Exception\Http\Status408') === true) {
+	class Requests_Exception_HTTP_408 extends WpOrg\Requests\Exception\Http\Status408 {}
+}
+if (class_exists('Requests_Exception_HTTP_409') === false && class_exists('WpOrg\Requests\Exception\Http\Status409') === true) {
+	class Requests_Exception_HTTP_409 extends WpOrg\Requests\Exception\Http\Status409 {}
+}
+if (class_exists('Requests_Exception_HTTP_410') === false && class_exists('WpOrg\Requests\Exception\Http\Status410') === true) {
+	class Requests_Exception_HTTP_410 extends WpOrg\Requests\Exception\Http\Status410 {}
+}
+if (class_exists('Requests_Exception_HTTP_411') === false && class_exists('WpOrg\Requests\Exception\Http\Status411') === true) {
+	class Requests_Exception_HTTP_411 extends WpOrg\Requests\Exception\Http\Status411 {}
+}
+if (class_exists('Requests_Exception_HTTP_412') === false && class_exists('WpOrg\Requests\Exception\Http\Status412') === true) {
+	class Requests_Exception_HTTP_412 extends WpOrg\Requests\Exception\Http\Status412 {}
+}
+if (class_exists('Requests_Exception_HTTP_413') === false && class_exists('WpOrg\Requests\Exception\Http\Status413') === true) {
+	class Requests_Exception_HTTP_413 extends WpOrg\Requests\Exception\Http\Status413 {}
+}
+if (class_exists('Requests_Exception_HTTP_414') === false && class_exists('WpOrg\Requests\Exception\Http\Status414') === true) {
+	class Requests_Exception_HTTP_414 extends WpOrg\Requests\Exception\Http\Status414 {}
+}
+if (class_exists('Requests_Exception_HTTP_415') === false && class_exists('WpOrg\Requests\Exception\Http\Status415') === true) {
+	class Requests_Exception_HTTP_415 extends WpOrg\Requests\Exception\Http\Status415 {}
+}
+if (class_exists('Requests_Exception_HTTP_416') === false && class_exists('WpOrg\Requests\Exception\Http\Status416') === true) {
+	class Requests_Exception_HTTP_416 extends WpOrg\Requests\Exception\Http\Status416 {}
+}
+if (class_exists('Requests_Exception_HTTP_417') === false && class_exists('WpOrg\Requests\Exception\Http\Status417') === true) {
+	class Requests_Exception_HTTP_417 extends WpOrg\Requests\Exception\Http\Status417 {}
+}
+if (class_exists('Requests_Exception_HTTP_418') === false && class_exists('WpOrg\Requests\Exception\Http\Status418') === true) {
+	class Requests_Exception_HTTP_418 extends WpOrg\Requests\Exception\Http\Status418 {}
+}
+if (class_exists('Requests_Exception_HTTP_428') === false && class_exists('WpOrg\Requests\Exception\Http\Status428') === true) {
+	class Requests_Exception_HTTP_428 extends WpOrg\Requests\Exception\Http\Status428 {}
+}
+if (class_exists('Requests_Exception_HTTP_429') === false && class_exists('WpOrg\Requests\Exception\Http\Status429') === true) {
+	class Requests_Exception_HTTP_429 extends WpOrg\Requests\Exception\Http\Status429 {}
+}
+if (class_exists('Requests_Exception_HTTP_431') === false && class_exists('WpOrg\Requests\Exception\Http\Status431') === true) {
+	class Requests_Exception_HTTP_431 extends WpOrg\Requests\Exception\Http\Status431 {}
+}
+if (class_exists('Requests_Exception_HTTP_500') === false && class_exists('WpOrg\Requests\Exception\Http\Status500') === true) {
+	class Requests_Exception_HTTP_500 extends WpOrg\Requests\Exception\Http\Status500 {}
+}
+if (class_exists('Requests_Exception_HTTP_501') === false && class_exists('WpOrg\Requests\Exception\Http\Status501') === true) {
+	class Requests_Exception_HTTP_501 extends WpOrg\Requests\Exception\Http\Status501 {}
+}
+if (class_exists('Requests_Exception_HTTP_502') === false && class_exists('WpOrg\Requests\Exception\Http\Status502') === true) {
+	class Requests_Exception_HTTP_502 extends WpOrg\Requests\Exception\Http\Status502 {}
+}
+if (class_exists('Requests_Exception_HTTP_503') === false && class_exists('WpOrg\Requests\Exception\Http\Status503') === true) {
+	class Requests_Exception_HTTP_503 extends WpOrg\Requests\Exception\Http\Status503 {}
+}
+if (class_exists('Requests_Exception_HTTP_504') === false && class_exists('WpOrg\Requests\Exception\Http\Status504') === true) {
+	class Requests_Exception_HTTP_504 extends WpOrg\Requests\Exception\Http\Status504 {}
+}
+if (class_exists('Requests_Exception_HTTP_505') === false && class_exists('WpOrg\Requests\Exception\Http\Status505') === true) {
+	class Requests_Exception_HTTP_505 extends WpOrg\Requests\Exception\Http\Status505 {}
+}
+if (class_exists('Requests_Exception_HTTP_511') === false && class_exists('WpOrg\Requests\Exception\Http\Status511') === true) {
+	class Requests_Exception_HTTP_511 extends WpOrg\Requests\Exception\Http\Status511 {}
+}
+if (class_exists('Requests_Exception_HTTP_Unknown') === false && class_exists('WpOrg\Requests\Exception\Http\StatusUnknown') === true) {
+	class Requests_Exception_HTTP_Unknown extends WpOrg\Requests\Exception\Http\StatusUnknown {}
+}
diff --git a/library/README.md b/library/README.md
new file mode 100644
index 000000000..d492c0f89
--- /dev/null
+++ b/library/README.md
@@ -0,0 +1,6 @@
+## The Library directory is deprecated.
+
+The files in this directory are only still in place to provide backward compatibility with Requests 1.x.
+Please see the release notes of Requests 2.0.0 on how to upgrade.
+
+This directory will be removed in Requests v 4.0.0.
diff --git a/library/Requests.php b/library/Requests.php
index 2400cb18e..05250640f 100644
--- a/library/Requests.php
+++ b/library/Requests.php
@@ -7,7 +7,30 @@
  * Based on concepts from SimplePie_File, RequestCore and WP_Http.
  *
  * @package Requests
+ *
+ * @deprecated 2.0.0
+ */
+
+/*
+ * Integrators who cannot yet upgrade to the PSR-4 class names can silence deprecations
+ * by defining a `REQUESTS_SILENCE_PSR0_DEPRECATIONS` constant and setting it to `true`.
+ * The constant needs to be defined before this class is required.
  */
+if (!defined('REQUESTS_SILENCE_PSR0_DEPRECATIONS') || REQUESTS_SILENCE_PSR0_DEPRECATIONS !== true) {
+	// phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_trigger_error
+	trigger_error(
+		'The PSR-0 `Requests_...` class names in the Request library are deprecated.'
+		. ' Switch to the PSR-4 `WpOrg\Requests\...` class names at your earliest convenience.',
+		E_USER_DEPRECATED
+	);
+
+	// Prevent the deprecation notice from being thrown twice.
+	if (!defined('REQUESTS_SILENCE_PSR0_DEPRECATIONS')) {
+		define('REQUESTS_SILENCE_PSR0_DEPRECATIONS', true);
+	}
+}
+
+require_once dirname(__DIR__) . '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/src/Requests.php';
 
 /**
  * Requests for PHP
@@ -17,972 +40,39 @@
  * Based on concepts from SimplePie_File, RequestCore and WP_Http.
  *
  * @package Requests
+ *
+ * @deprecated 2.0.0 Use `WpOrg\Requests\Requests` instead for the actual functionality and
+ *                   use `WpOrg\Requests\Autoload` for the autoloading.
  */
-class Requests {
-	/**
-	 * POST method
-	 *
-	 * @var string
-	 */
-	const POST = 'POST';
+class Requests extends WpOrg\Requests\Requests {
 
 	/**
-	 * PUT method
+	 * Deprecated autoloader for Requests.
 	 *
-	 * @var string
-	 */
-	const PUT = 'PUT';
-
-	/**
-	 * GET method
-	 *
-	 * @var string
-	 */
-	const GET = 'GET';
-
-	/**
-	 * HEAD method
-	 *
-	 * @var string
-	 */
-	const HEAD = 'HEAD';
-
-	/**
-	 * DELETE method
-	 *
-	 * @var string
-	 */
-	const DELETE = 'DELETE';
-
-	/**
-	 * OPTIONS method
-	 *
-	 * @var string
-	 */
-	const OPTIONS = 'OPTIONS';
-
-	/**
-	 * TRACE method
-	 *
-	 * @var string
-	 */
-	const TRACE = 'TRACE';
-
-	/**
-	 * PATCH method
-	 *
-	 * @link https://tools.ietf.org/html/rfc5789
-	 * @var string
-	 */
-	const PATCH = 'PATCH';
-
-	/**
-	 * Default size of buffer size to read streams
-	 *
-	 * @var integer
-	 */
-	const BUFFER_SIZE = 1160;
-
-	/**
-	 * Current version of Requests
-	 *
-	 * @var string
-	 */
-	const VERSION = '1.8.1';
-
-	/**
-	 * Registered transport classes
-	 *
-	 * @var array
-	 */
-	protected static $transports = array();
-
-	/**
-	 * Selected transport name
-	 *
-	 * Use {@see get_transport()} instead
-	 *
-	 * @var array
-	 */
-	public static $transport = array();
-
-	/**
-	 * Default certificate path.
-	 *
-	 * @see Requests::get_certificate_path()
-	 * @see Requests::set_certificate_path()
-	 *
-	 * @var string
-	 */
-	protected static $certificate_path;
-
-	/**
-	 * This is a static class, do not instantiate it
-	 *
-	 * @codeCoverageIgnore
-	 */
-	private function __construct() {}
-
-	/**
-	 * Autoloader for Requests
-	 *
-	 * Register this with {@see register_autoloader()} if you'd like to avoid
-	 * having to create your own.
-	 *
-	 * (You can also use `spl_autoload_register` directly if you'd prefer.)
+	 * @deprecated 2.0.0 Use the `WpOrg\Requests\Autoload::load()` method instead.
 	 *
 	 * @codeCoverageIgnore
 	 *
 	 * @param string $class Class name to load
 	 */
 	public static function autoloader($class) {
-		// Check that the class starts with "Requests"
-		if (strpos($class, 'Requests') !== 0) {
-			return;
+		if (class_exists('WpOrg\Requests\Autoload') === false) {
+			require_once dirname(__DIR__) . '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/src/Autoload.php';
 		}
 
-		$file = str_replace('_', '/', $class);
-		if (file_exists(__DIR__ . '/' . $file . '.php')) {
-			require_once __DIR__ . '/' . $file . '.php';
-		}
+		return WpOrg\Requests\Autoload::load($class);
 	}
 
 	/**
 	 * Register the built-in autoloader
 	 *
+	 * @deprecated 2.0.0 Include the `WpOrg\Requests\Autoload` class and
+	 *                   call `WpOrg\Requests\Autoload::register()` instead.
+	 *
 	 * @codeCoverageIgnore
 	 */
 	public static function register_autoloader() {
-		spl_autoload_register(array(static::class, 'autoloader'));
-	}
-
-	/**
-	 * Register a transport
-	 *
-	 * @param string $transport Transport class to add, must support the Requests_Transport interface
-	 */
-	public static function add_transport($transport) {
-		if (empty(self::$transports)) {
-			self::$transports = array(
-				Requests_Transport_cURL::class,
-				Requests_Transport_fsockopen::class,
-			);
-		}
-
-		self::$transports = array_merge(self::$transports, array($transport));
-	}
-
-	/**
-	 * Get a working transport
-	 *
-	 * @throws Requests_Exception If no valid transport is found (`notransport`)
-	 * @return Requests_Transport
-	 */
-	protected static function get_transport($capabilities = array()) {
-		// Caching code, don't bother testing coverage
-		// @codeCoverageIgnoreStart
-		// array of capabilities as a string to be used as an array key
-		ksort($capabilities);
-		$cap_string = serialize($capabilities);
-
-		// Don't search for a transport if it's already been done for these $capabilities
-		if (isset(self::$transport[$cap_string]) && self::$transport[$cap_string] !== null) {
-			$class = self::$transport[$cap_string];
-			return new $class();
-		}
-		// @codeCoverageIgnoreEnd
-
-		if (empty(self::$transports)) {
-			self::$transports = array(
-				Requests_Transport_cURL::class,
-				Requests_Transport_fsockopen::class,
-			);
-		}
-
-		// Find us a working transport
-		foreach (self::$transports as $class) {
-			if (!class_exists($class)) {
-				continue;
-			}
-
-			$result = call_user_func(array($class, 'test'), $capabilities);
-			if ($result) {
-				self::$transport[$cap_string] = $class;
-				break;
-			}
-		}
-		if (self::$transport[$cap_string] === null) {
-			throw new Requests_Exception('No working transports found', 'notransport', self::$transports);
-		}
-
-		$class = self::$transport[$cap_string];
-		return new $class();
-	}
-
-	/**#@+
-	 * @see request()
-	 * @param string $url
-	 * @param array $headers
-	 * @param array $options
-	 * @return Requests_Response
-	 */
-	/**
-	 * Send a GET request
-	 */
-	public static function get($url, $headers = array(), $options = array()) {
-		return self::request($url, $headers, null, self::GET, $options);
-	}
-
-	/**
-	 * Send a HEAD request
-	 */
-	public static function head($url, $headers = array(), $options = array()) {
-		return self::request($url, $headers, null, self::HEAD, $options);
-	}
-
-	/**
-	 * Send a DELETE request
-	 */
-	public static function delete($url, $headers = array(), $options = array()) {
-		return self::request($url, $headers, null, self::DELETE, $options);
-	}
-
-	/**
-	 * Send a TRACE request
-	 */
-	public static function trace($url, $headers = array(), $options = array()) {
-		return self::request($url, $headers, null, self::TRACE, $options);
-	}
-	/**#@-*/
-
-	/**#@+
-	 * @see request()
-	 * @param string $url
-	 * @param array $headers
-	 * @param array $data
-	 * @param array $options
-	 * @return Requests_Response
-	 */
-	/**
-	 * Send a POST request
-	 */
-	public static function post($url, $headers = array(), $data = array(), $options = array()) {
-		return self::request($url, $headers, $data, self::POST, $options);
-	}
-	/**
-	 * Send a PUT request
-	 */
-	public static function put($url, $headers = array(), $data = array(), $options = array()) {
-		return self::request($url, $headers, $data, self::PUT, $options);
-	}
-
-	/**
-	 * Send an OPTIONS request
-	 */
-	public static function options($url, $headers = array(), $data = array(), $options = array()) {
-		return self::request($url, $headers, $data, self::OPTIONS, $options);
-	}
-
-	/**
-	 * Send a PATCH request
-	 *
-	 * Note: Unlike {@see post} and {@see put}, `$headers` is required, as the
-	 * specification recommends that should send an ETag
-	 *
-	 * @link https://tools.ietf.org/html/rfc5789
-	 */
-	public static function patch($url, $headers, $data = array(), $options = array()) {
-		return self::request($url, $headers, $data, self::PATCH, $options);
-	}
-	/**#@-*/
-
-	/**
-	 * Main interface for HTTP requests
-	 *
-	 * This method initiates a request and sends it via a transport before
-	 * parsing.
-	 *
-	 * The `$options` parameter takes an associative array with the following
-	 * options:
-	 *
-	 * - `timeout`: How long should we wait for a response?
-	 *    Note: for cURL, a minimum of 1 second applies, as DNS resolution
-	 *    operates at second-resolution only.
-	 *    (float, seconds with a millisecond precision, default: 10, example: 0.01)
-	 * - `connect_timeout`: How long should we wait while trying to connect?
-	 *    (float, seconds with a millisecond precision, default: 10, example: 0.01)
-	 * - `useragent`: Useragent to send to the server
-	 *    (string, default: php-requests/$version)
-	 * - `follow_redirects`: Should we follow 3xx redirects?
-	 *    (boolean, default: true)
-	 * - `redirects`: How many times should we redirect before erroring?
-	 *    (integer, default: 10)
-	 * - `blocking`: Should we block processing on this request?
-	 *    (boolean, default: true)
-	 * - `filename`: File to stream the body to instead.
-	 *    (string|boolean, default: false)
-	 * - `auth`: Authentication handler or array of user/password details to use
-	 *    for Basic authentication
-	 *    (Requests_Auth|array|boolean, default: false)
-	 * - `proxy`: Proxy details to use for proxy by-passing and authentication
-	 *    (Requests_Proxy|array|string|boolean, default: false)
-	 * - `max_bytes`: Limit for the response body size.
-	 *    (integer|boolean, default: false)
-	 * - `idn`: Enable IDN parsing
-	 *    (boolean, default: true)
-	 * - `transport`: Custom transport. Either a class name, or a
-	 *    transport object. Defaults to the first working transport from
-	 *    {@see getTransport()}
-	 *    (string|Requests_Transport, default: {@see getTransport()})
-	 * - `hooks`: Hooks handler.
-	 *    (Requests_Hooker, default: new Requests_Hooks())
-	 * - `verify`: Should we verify SSL certificates? Allows passing in a custom
-	 *    certificate file as a string. (Using true uses the system-wide root
-	 *    certificate store instead, but this may have different behaviour
-	 *    across transports.)
-	 *    (string|boolean, default: library/Requests/Transport/cacert.pem)
-	 * - `verifyname`: Should we verify the common name in the SSL certificate?
-	 *    (boolean, default: true)
-	 * - `data_format`: How should we send the `$data` parameter?
-	 *    (string, one of 'query' or 'body', default: 'query' for
-	 *    HEAD/GET/DELETE, 'body' for POST/PUT/OPTIONS/PATCH)
-	 *
-	 * @throws Requests_Exception On invalid URLs (`nonhttp`)
-	 *
-	 * @param string $url URL to request
-	 * @param array $headers Extra headers to send with the request
-	 * @param array|null $data Data to send either as a query string for GET/HEAD requests, or in the body for POST requests
-	 * @param string $type HTTP request type (use Requests constants)
-	 * @param array $options Options for the request (see description for more information)
-	 * @return Requests_Response
-	 */
-	public static function request($url, $headers = array(), $data = array(), $type = self::GET, $options = array()) {
-		if (empty($options['type'])) {
-			$options['type'] = $type;
-		}
-		$options = array_merge(self::get_default_options(), $options);
-
-		self::set_defaults($url, $headers, $data, $type, $options);
-
-		$options['hooks']->dispatch('requests.before_request', array(&$url, &$headers, &$data, &$type, &$options));
-
-		if (!empty($options['transport'])) {
-			$transport = $options['transport'];
-
-			if (is_string($options['transport'])) {
-				$transport = new $transport();
-			}
-		}
-		else {
-			$need_ssl     = (stripos($url, 'https://') === 0);
-			$capabilities = array('ssl' => $need_ssl);
-			$transport    = self::get_transport($capabilities);
-		}
-		$response = $transport->request($url, $headers, $data, $options);
-
-		$options['hooks']->dispatch('requests.before_parse', array(&$response, $url, $headers, $data, $type, $options));
-
-		return self::parse_response($response, $url, $headers, $data, $options);
-	}
-
-	/**
-	 * Send multiple HTTP requests simultaneously
-	 *
-	 * The `$requests` parameter takes an associative or indexed array of
-	 * request fields. The key of each request can be used to match up the
-	 * request with the returned data, or with the request passed into your
-	 * `multiple.request.complete` callback.
-	 *
-	 * The request fields value is an associative array with the following keys:
-	 *
-	 * - `url`: Request URL Same as the `$url` parameter to
-	 *    {@see Requests::request}
-	 *    (string, required)
-	 * - `headers`: Associative array of header fields. Same as the `$headers`
-	 *    parameter to {@see Requests::request}
-	 *    (array, default: `array()`)
-	 * - `data`: Associative array of data fields or a string. Same as the
-	 *    `$data` parameter to {@see Requests::request}
-	 *    (array|string, default: `array()`)
-	 * - `type`: HTTP request type (use Requests constants). Same as the `$type`
-	 *    parameter to {@see Requests::request}
-	 *    (string, default: `Requests::GET`)
-	 * - `cookies`: Associative array of cookie name to value, or cookie jar.
-	 *    (array|Requests_Cookie_Jar)
-	 *
-	 * If the `$options` parameter is specified, individual requests will
-	 * inherit options from it. This can be used to use a single hooking system,
-	 * or set all the types to `Requests::POST`, for example.
-	 *
-	 * In addition, the `$options` parameter takes the following global options:
-	 *
-	 * - `complete`: A callback for when a request is complete. Takes two
-	 *    parameters, a Requests_Response/Requests_Exception reference, and the
-	 *    ID from the request array (Note: this can also be overridden on a
-	 *    per-request basis, although that's a little silly)
-	 *    (callback)
-	 *
-	 * @param array $requests Requests data (see description for more information)
-	 * @param array $options Global and default options (see {@see Requests::request})
-	 * @return array Responses (either Requests_Response or a Requests_Exception object)
-	 */
-	public static function request_multiple($requests, $options = array()) {
-		$options = array_merge(self::get_default_options(true), $options);
-
-		if (!empty($options['hooks'])) {
-			$options['hooks']->register('transport.internal.parse_response', array(static::class, 'parse_multiple'));
-			if (!empty($options['complete'])) {
-				$options['hooks']->register('multiple.request.complete', $options['complete']);
-			}
-		}
-
-		foreach ($requests as $id => &$request) {
-			if (!isset($request['headers'])) {
-				$request['headers'] = array();
-			}
-			if (!isset($request['data'])) {
-				$request['data'] = array();
-			}
-			if (!isset($request['type'])) {
-				$request['type'] = self::GET;
-			}
-			if (!isset($request['options'])) {
-				$request['options']         = $options;
-				$request['options']['type'] = $request['type'];
-			}
-			else {
-				if (empty($request['options']['type'])) {
-					$request['options']['type'] = $request['type'];
-				}
-				$request['options'] = array_merge($options, $request['options']);
-			}
-
-			self::set_defaults($request['url'], $request['headers'], $request['data'], $request['type'], $request['options']);
-
-			// Ensure we only hook in once
-			if ($request['options']['hooks'] !== $options['hooks']) {
-				$request['options']['hooks']->register('transport.internal.parse_response', array(static::class, 'parse_multiple'));
-				if (!empty($request['options']['complete'])) {
-					$request['options']['hooks']->register('multiple.request.complete', $request['options']['complete']);
-				}
-			}
-		}
-		unset($request);
-
-		if (!empty($options['transport'])) {
-			$transport = $options['transport'];
-
-			if (is_string($options['transport'])) {
-				$transport = new $transport();
-			}
-		}
-		else {
-			$transport = self::get_transport();
-		}
-		$responses = $transport->request_multiple($requests, $options);
-
-		foreach ($responses as $id => &$response) {
-			// If our hook got messed with somehow, ensure we end up with the
-			// correct response
-			if (is_string($response)) {
-				$request = $requests[$id];
-				self::parse_multiple($response, $request);
-				$request['options']['hooks']->dispatch('multiple.request.complete', array(&$response, $id));
-			}
-		}
-
-		return $responses;
-	}
-
-	/**
-	 * Get the default options
-	 *
-	 * @see Requests::request() for values returned by this method
-	 * @param boolean $multirequest Is this a multirequest?
-	 * @return array Default option values
-	 */
-	protected static function get_default_options($multirequest = false) {
-		$defaults = array(
-			'timeout'          => 10,
-			'connect_timeout'  => 10,
-			'useragent'        => 'php-requests/' . self::VERSION,
-			'protocol_version' => 1.1,
-			'redirected'       => 0,
-			'redirects'        => 10,
-			'follow_redirects' => true,
-			'blocking'         => true,
-			'type'             => self::GET,
-			'filename'         => false,
-			'auth'             => false,
-			'proxy'            => false,
-			'cookies'          => false,
-			'max_bytes'        => false,
-			'idn'              => true,
-			'hooks'            => null,
-			'transport'        => null,
-			'verify'           => self::get_certificate_path(),
-			'verifyname'       => true,
-		);
-		if ($multirequest !== false) {
-			$defaults['complete'] = null;
-		}
-		return $defaults;
-	}
-
-	/**
-	 * Get default certificate path.
-	 *
-	 * @return string Default certificate path.
-	 */
-	public static function get_certificate_path() {
-		if (!empty(self::$certificate_path)) {
-			return self::$certificate_path;
-		}
-
-		return __DIR__ . '/Requests/Transport/cacert.pem';
-	}
-
-	/**
-	 * Set default certificate path.
-	 *
-	 * @param string $path Certificate path, pointing to a PEM file.
-	 */
-	public static function set_certificate_path($path) {
-		self::$certificate_path = $path;
-	}
-
-	/**
-	 * Set the default values
-	 *
-	 * @param string $url URL to request
-	 * @param array $headers Extra headers to send with the request
-	 * @param array|null $data Data to send either as a query string for GET/HEAD requests, or in the body for POST requests
-	 * @param string $type HTTP request type
-	 * @param array $options Options for the request
-	 * @return array $options
-	 */
-	protected static function set_defaults(&$url, &$headers, &$data, &$type, &$options) {
-		if (!preg_match('/^http(s)?:\/\//i', $url, $matches)) {
-			throw new Requests_Exception('Only HTTP(S) requests are handled.', 'nonhttp', $url);
-		}
-
-		if (empty($options['hooks'])) {
-			$options['hooks'] = new Requests_Hooks();
-		}
-
-		if (is_array($options['auth'])) {
-			$options['auth'] = new Requests_Auth_Basic($options['auth']);
-		}
-		if ($options['auth'] !== false) {
-			$options['auth']->register($options['hooks']);
-		}
-
-		if (is_string($options['proxy']) || is_array($options['proxy'])) {
-			$options['proxy'] = new Requests_Proxy_HTTP($options['proxy']);
-		}
-		if ($options['proxy'] !== false) {
-			$options['proxy']->register($options['hooks']);
-		}
-
-		if (is_array($options['cookies'])) {
-			$options['cookies'] = new Requests_Cookie_Jar($options['cookies']);
-		}
-		elseif (empty($options['cookies'])) {
-			$options['cookies'] = new Requests_Cookie_Jar();
-		}
-		if ($options['cookies'] !== false) {
-			$options['cookies']->register($options['hooks']);
-		}
-
-		if ($options['idn'] !== false) {
-			$iri       = new Requests_IRI($url);
-			$iri->host = Requests_IDNAEncoder::encode($iri->ihost);
-			$url       = $iri->uri;
-		}
-
-		// Massage the type to ensure we support it.
-		$type = strtoupper($type);
-
-		if (!isset($options['data_format'])) {
-			if (in_array($type, array(self::HEAD, self::GET, self::DELETE), true)) {
-				$options['data_format'] = 'query';
-			}
-			else {
-				$options['data_format'] = 'body';
-			}
-		}
-	}
-
-	/**
-	 * HTTP response parser
-	 *
-	 * @throws Requests_Exception On missing head/body separator (`requests.no_crlf_separator`)
-	 * @throws Requests_Exception On missing head/body separator (`noversion`)
-	 * @throws Requests_Exception On missing head/body separator (`toomanyredirects`)
-	 *
-	 * @param string $headers Full response text including headers and body
-	 * @param string $url Original request URL
-	 * @param array $req_headers Original $headers array passed to {@link request()}, in case we need to follow redirects
-	 * @param array $req_data Original $data array passed to {@link request()}, in case we need to follow redirects
-	 * @param array $options Original $options array passed to {@link request()}, in case we need to follow redirects
-	 * @return Requests_Response
-	 */
-	protected static function parse_response($headers, $url, $req_headers, $req_data, $options) {
-		$return = new Requests_Response();
-		if (!$options['blocking']) {
-			return $return;
-		}
-
-		$return->raw  = $headers;
-		$return->url  = (string) $url;
-		$return->body = '';
-
-		if (!$options['filename']) {
-			$pos = strpos($headers, "\r\n\r\n");
-			if ($pos === false) {
-				// Crap!
-				throw new Requests_Exception('Missing header/body separator', 'requests.no_crlf_separator');
-			}
-
-			$headers = substr($return->raw, 0, $pos);
-			// Headers will always be separated from the body by two new lines - `\n\r\n\r`.
-			$body = substr($return->raw, $pos + 4);
-			if (!empty($body)) {
-				$return->body = $body;
-			}
-		}
-		// Pretend CRLF = LF for compatibility (RFC 2616, section 19.3)
-		$headers = str_replace("\r\n", "\n", $headers);
-		// Unfold headers (replace [CRLF] 1*( SP | HT ) with SP) as per RFC 2616 (section 2.2)
-		$headers = preg_replace('/\n[ \t]/', ' ', $headers);
-		$headers = explode("\n", $headers);
-		preg_match('#^HTTP/(1\.\d)[ \t]+(\d+)#i', array_shift($headers), $matches);
-		if (empty($matches)) {
-			throw new Requests_Exception('Response could not be parsed', 'noversion', $headers);
-		}
-		$return->protocol_version = (float) $matches[1];
-		$return->status_code      = (int) $matches[2];
-		if ($return->status_code >= 200 && $return->status_code < 300) {
-			$return->success = true;
-		}
-
-		foreach ($headers as $header) {
-			list($key, $value) = explode(':', $header, 2);
-			$value             = trim($value);
-			preg_replace('#(\s+)#i', ' ', $value);
-			$return->headers[$key] = $value;
-		}
-		if (isset($return->headers['transfer-encoding'])) {
-			$return->body = self::decode_chunked($return->body);
-			unset($return->headers['transfer-encoding']);
-		}
-		if (isset($return->headers['content-encoding'])) {
-			$return->body = self::decompress($return->body);
-		}
-
-		//fsockopen and cURL compatibility
-		if (isset($return->headers['connection'])) {
-			unset($return->headers['connection']);
-		}
-
-		$options['hooks']->dispatch('requests.before_redirect_check', array(&$return, $req_headers, $req_data, $options));
-
-		if ($return->is_redirect() && $options['follow_redirects'] === true) {
-			if (isset($return->headers['location']) && $options['redirected'] < $options['redirects']) {
-				if ($return->status_code === 303) {
-					$options['type'] = self::GET;
-				}
-				$options['redirected']++;
-				$location = $return->headers['location'];
-				if (strpos($location, 'http://') !== 0 && strpos($location, 'https://') !== 0) {
-					// relative redirect, for compatibility make it absolute
-					$location = Requests_IRI::absolutize($url, $location);
-					$location = $location->uri;
-				}
-
-				$hook_args = array(
-					&$location,
-					&$req_headers,
-					&$req_data,
-					&$options,
-					$return,
-				);
-				$options['hooks']->dispatch('requests.before_redirect', $hook_args);
-				$redirected            = self::request($location, $req_headers, $req_data, $options['type'], $options);
-				$redirected->history[] = $return;
-				return $redirected;
-			}
-			elseif ($options['redirected'] >= $options['redirects']) {
-				throw new Requests_Exception('Too many redirects', 'toomanyredirects', $return);
-			}
-		}
-
-		$return->redirects = $options['redirected'];
-
-		$options['hooks']->dispatch('requests.after_request', array(&$return, $req_headers, $req_data, $options));
-		return $return;
-	}
-
-	/**
-	 * Callback for `transport.internal.parse_response`
-	 *
-	 * Internal use only. Converts a raw HTTP response to a Requests_Response
-	 * while still executing a multiple request.
-	 *
-	 * @param string $response Full response text including headers and body (will be overwritten with Response instance)
-	 * @param array $request Request data as passed into {@see Requests::request_multiple()}
-	 * @return null `$response` is either set to a Requests_Response instance, or a Requests_Exception object
-	 */
-	public static function parse_multiple(&$response, $request) {
-		try {
-			$url      = $request['url'];
-			$headers  = $request['headers'];
-			$data     = $request['data'];
-			$options  = $request['options'];
-			$response = self::parse_response($response, $url, $headers, $data, $options);
-		}
-		catch (Requests_Exception $e) {
-			$response = $e;
-		}
-	}
-
-	/**
-	 * Decoded a chunked body as per RFC 2616
-	 *
-	 * @see https://tools.ietf.org/html/rfc2616#section-3.6.1
-	 * @param string $data Chunked body
-	 * @return string Decoded body
-	 */
-	protected static function decode_chunked($data) {
-		if (!preg_match('/^([0-9a-f]+)(?:;(?:[\w-]*)(?:=(?:(?:[\w-]*)*|"(?:[^\r\n])*"))?)*\r\n/i', trim($data))) {
-			return $data;
-		}
-
-		$decoded = '';
-		$encoded = $data;
-
-		while (true) {
-			$is_chunked = (bool) preg_match('/^([0-9a-f]+)(?:;(?:[\w-]*)(?:=(?:(?:[\w-]*)*|"(?:[^\r\n])*"))?)*\r\n/i', $encoded, $matches);
-			if (!$is_chunked) {
-				// Looks like it's not chunked after all
-				return $data;
-			}
-
-			$length = hexdec(trim($matches[1]));
-			if ($length === 0) {
-				// Ignore trailer headers
-				return $decoded;
-			}
-
-			$chunk_length = strlen($matches[0]);
-			$decoded     .= substr($encoded, $chunk_length, $length);
-			$encoded      = substr($encoded, $chunk_length + $length + 2);
-
-			if (trim($encoded) === '0' || empty($encoded)) {
-				return $decoded;
-			}
-		}
-
-		// We'll never actually get down here
-		// @codeCoverageIgnoreStart
-	}
-	// @codeCoverageIgnoreEnd
-
-	/**
-	 * Convert a key => value array to a 'key: value' array for headers
-	 *
-	 * @param array $array Dictionary of header values
-	 * @return array List of headers
-	 */
-	public static function flatten($array) {
-		$return = array();
-		foreach ($array as $key => $value) {
-			$return[] = sprintf('%s: %s', $key, $value);
-		}
-		return $return;
-	}
-
-	/**
-	 * Decompress an encoded body
-	 *
-	 * Implements gzip, compress and deflate. Guesses which it is by attempting
-	 * to decode.
-	 *
-	 * @param string $data Compressed data in one of the above formats
-	 * @return string Decompressed string
-	 */
-	public static function decompress($data) {
-		if (substr($data, 0, 2) !== "\x1f\x8b" && substr($data, 0, 2) !== "\x78\x9c") {
-			// Not actually compressed. Probably cURL ruining this for us.
-			return $data;
-		}
-
-		if (function_exists('gzdecode')) {
-			$decoded = @gzdecode($data);
-			if ($decoded !== false) {
-				return $decoded;
-			}
-		}
-
-		if (function_exists('gzinflate')) {
-			$decoded = @gzinflate($data);
-			if ($decoded !== false) {
-				return $decoded;
-			}
-		}
-
-		$decoded = self::compatible_gzinflate($data);
-		if ($decoded !== false) {
-			return $decoded;
-		}
-
-		if (function_exists('gzuncompress')) {
-			$decoded = @gzuncompress($data);
-			if ($decoded !== false) {
-				return $decoded;
-			}
-		}
-
-		return $data;
-	}
-
-	/**
-	 * Decompression of deflated string while staying compatible with the majority of servers.
-	 *
-	 * Certain Servers will return deflated data with headers which PHP's gzinflate()
-	 * function cannot handle out of the box. The following function has been created from
-	 * various snippets on the gzinflate() PHP documentation.
-	 *
-	 * Warning: Magic numbers within. Due to the potential different formats that the compressed
-	 * data may be returned in, some "magic offsets" are needed to ensure proper decompression
-	 * takes place. For a simple progmatic way to determine the magic offset in use, see:
-	 * https://core.trac.wordpress.org/ticket/18273
-	 *
-	 * @since 2.8.1
-	 * @link https://core.trac.wordpress.org/ticket/18273
-	 * @link https://www.php.net/gzinflate#70875
-	 * @link https://www.php.net/gzinflate#77336
-	 *
-	 * @param string $gz_data String to decompress.
-	 * @return string|bool False on failure.
-	 */
-	public static function compatible_gzinflate($gz_data) {
-		// Compressed data might contain a full zlib header, if so strip it for
-		// gzinflate()
-		if (substr($gz_data, 0, 3) === "\x1f\x8b\x08") {
-			$i   = 10;
-			$flg = ord(substr($gz_data, 3, 1));
-			if ($flg > 0) {
-				if ($flg & 4) {
-					list($xlen) = unpack('v', substr($gz_data, $i, 2));
-					$i         += 2 + $xlen;
-				}
-				if ($flg & 8) {
-					$i = strpos($gz_data, "\0", $i) + 1;
-				}
-				if ($flg & 16) {
-					$i = strpos($gz_data, "\0", $i) + 1;
-				}
-				if ($flg & 2) {
-					$i += 2;
-				}
-			}
-			$decompressed = self::compatible_gzinflate(substr($gz_data, $i));
-			if ($decompressed !== false) {
-				return $decompressed;
-			}
-		}
-
-		// If the data is Huffman Encoded, we must first strip the leading 2
-		// byte Huffman marker for gzinflate()
-		// The response is Huffman coded by many compressors such as
-		// java.util.zip.Deflater, Ruby’s Zlib::Deflate, and .NET's
-		// System.IO.Compression.DeflateStream.
-		//
-		// See https://decompres.blogspot.com/ for a quick explanation of this
-		// data type
-		$huffman_encoded = false;
-
-		// low nibble of first byte should be 0x08
-		list(, $first_nibble) = unpack('h', $gz_data);
-
-		// First 2 bytes should be divisible by 0x1F
-		list(, $first_two_bytes) = unpack('n', $gz_data);
-
-		if ($first_nibble === 0x08 && ($first_two_bytes % 0x1F) === 0) {
-			$huffman_encoded = true;
-		}
-
-		if ($huffman_encoded) {
-			$decompressed = @gzinflate(substr($gz_data, 2));
-			if ($decompressed !== false) {
-				return $decompressed;
-			}
-		}
-
-		if (substr($gz_data, 0, 4) === "\x50\x4b\x03\x04") {
-			// ZIP file format header
-			// Offset 6: 2 bytes, General-purpose field
-			// Offset 26: 2 bytes, filename length
-			// Offset 28: 2 bytes, optional field length
-			// Offset 30: Filename field, followed by optional field, followed
-			// immediately by data
-			list(, $general_purpose_flag) = unpack('v', substr($gz_data, 6, 2));
-
-			// If the file has been compressed on the fly, 0x08 bit is set of
-			// the general purpose field. We can use this to differentiate
-			// between a compressed document, and a ZIP file
-			$zip_compressed_on_the_fly = ((0x08 & $general_purpose_flag) === 0x08);
-
-			if (!$zip_compressed_on_the_fly) {
-				// Don't attempt to decode a compressed zip file
-				return $gz_data;
-			}
-
-			// Determine the first byte of data, based on the above ZIP header
-			// offsets:
-			$first_file_start = array_sum(unpack('v2', substr($gz_data, 26, 4)));
-			$decompressed     = @gzinflate(substr($gz_data, 30 + $first_file_start));
-			if ($decompressed !== false) {
-				return $decompressed;
-			}
-			return false;
-		}
-
-		// Finally fall back to straight gzinflate
-		$decompressed = @gzinflate($gz_data);
-		if ($decompressed !== false) {
-			return $decompressed;
-		}
-
-		// Fallback for all above failing, not expected, but included for
-		// debugging and preventing regressions and to track stats
-		$decompressed = @gzinflate(substr($gz_data, 2));
-		if ($decompressed !== false) {
-			return $decompressed;
-		}
-
-		return false;
-	}
-
-	public static function match_domain($host, $reference) {
-		// Check for a direct match
-		if ($host === $reference) {
-			return true;
-		}
-
-		// Calculate the valid wildcard match if the host is not an IP address
-		// Also validates that the host has 3 parts or more, as per Firefox's
-		// ruleset.
-		$parts = explode('.', $host);
-		if (ip2long($host) === false && count($parts) >= 3) {
-			$parts[0] = '*';
-			$wildcard = implode('.', $parts);
-			if ($wildcard === $reference) {
-				return true;
-			}
-		}
-
-		return false;
+		require_once dirname(__DIR__) . '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/src/Autoload.php';
+		WpOrg\Requests\Autoload::register();
 	}
 }
diff --git a/library/Requests/Exception/InvalidArgument.php b/library/Requests/Exception/InvalidArgument.php
deleted file mode 100644
index 6553742d3..000000000
--- a/library/Requests/Exception/InvalidArgument.php
+++ /dev/null
@@ -1,8 +0,0 @@
-<?php
-
-/**
- * Exception for an invalid argument passed.
- *
- * @package Requests
- */
-class Requests_Exception_InvalidArgument extends InvalidArgumentException {}
diff --git a/library/Requests/Exception/Transport.php b/library/Requests/Exception/Transport.php
deleted file mode 100644
index e60b4884c..000000000
--- a/library/Requests/Exception/Transport.php
+++ /dev/null
@@ -1,5 +0,0 @@
-<?php
-
-class Requests_Exception_Transport extends Requests_Exception {
-
-}
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index d14f496a5..16cba6d73 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -19,7 +19,7 @@
 
 	<filter>
 		<whitelist addUncoveredFilesFromWhitelist="true">
-			<directory suffix=".php">library</directory>
+			<directory suffix=".php">src</directory>
 		</whitelist>
 	</filter>
 </phpunit>
diff --git a/library/Requests/Auth.php b/src/Auth.php
similarity index 54%
rename from library/Requests/Auth.php
rename to src/Auth.php
index 914c7449c..a3599b5a2 100644
--- a/library/Requests/Auth.php
+++ b/src/Auth.php
@@ -6,6 +6,10 @@
  * @subpackage Authentication
  */
 
+namespace WpOrg\Requests;
+
+use WpOrg\Requests\Hooks;
+
 /**
  * Authentication provider interface
  *
@@ -14,20 +18,20 @@
  * Parameters should be passed via the constructor where possible, as this
  * makes it much easier for users to use your provider.
  *
- * @see Requests_Hooks
+ * @see \WpOrg\Requests\Hooks
  * @package Requests
  * @subpackage Authentication
  */
-interface Requests_Auth {
+interface Auth {
 	/**
 	 * Register hooks as needed
 	 *
-	 * This method is called in {@see Requests::request} when the user has set
-	 * an instance as the 'auth' option. Use this callback to register all the
+	 * This method is called in {@see \WpOrg\Requests\Requests::request} when the user
+	 * has set an instance as the 'auth' option. Use this callback to register all the
 	 * hooks you'll need.
 	 *
-	 * @see Requests_Hooks::register
-	 * @param Requests_Hooks $hooks Hook system
+	 * @see \WpOrg\Requests\Hooks::register
+	 * @param \WpOrg\Requests\Hooks $hooks Hook system
 	 */
-	public function register(Requests_Hooks $hooks);
+	public function register(Hooks $hooks);
 }
diff --git a/library/Requests/Auth/Basic.php b/src/Auth/Basic.php
similarity index 79%
rename from library/Requests/Auth/Basic.php
rename to src/Auth/Basic.php
index 68d15bd5d..83bd94979 100644
--- a/library/Requests/Auth/Basic.php
+++ b/src/Auth/Basic.php
@@ -6,6 +6,12 @@
  * @subpackage Authentication
  */
 
+namespace WpOrg\Requests\Auth;
+
+use WpOrg\Requests\Auth;
+use WpOrg\Requests\Exception;
+use WpOrg\Requests\Hooks;
+
 /**
  * Basic Authentication provider
  *
@@ -15,7 +21,7 @@
  * @package Requests
  * @subpackage Authentication
  */
-class Requests_Auth_Basic implements Requests_Auth {
+class Basic implements Auth {
 	/**
 	 * Username
 	 *
@@ -33,13 +39,13 @@ class Requests_Auth_Basic implements Requests_Auth {
 	/**
 	 * Constructor
 	 *
-	 * @throws Requests_Exception On incorrect number of arguments (`authbasicbadargs`)
+	 * @throws \WpOrg\Requests\Exception On incorrect number of arguments (`authbasicbadargs`)
 	 * @param array|null $args Array of user and password. Must have exactly two elements
 	 */
 	public function __construct($args = null) {
 		if (is_array($args)) {
 			if (count($args) !== 2) {
-				throw new Requests_Exception('Invalid number of arguments', 'authbasicbadargs');
+				throw new Exception('Invalid number of arguments', 'authbasicbadargs');
 			}
 
 			list($this->user, $this->pass) = $args;
@@ -51,9 +57,9 @@ public function __construct($args = null) {
 	 *
 	 * @see curl_before_send
 	 * @see fsockopen_header
-	 * @param Requests_Hooks $hooks Hook system
+	 * @param \WpOrg\Requests\Hooks $hooks Hook system
 	 */
-	public function register(Requests_Hooks $hooks) {
+	public function register(Hooks $hooks) {
 		$hooks->register('curl.before_send', array($this, 'curl_before_send'));
 		$hooks->register('fsockopen.after_headers', array($this, 'fsockopen_header'));
 	}
diff --git a/src/Autoload.php b/src/Autoload.php
new file mode 100644
index 000000000..4c1417cf1
--- /dev/null
+++ b/src/Autoload.php
@@ -0,0 +1,182 @@
+<?php
+/**
+ * Autoloader for Requests for PHP.
+ *
+ * Include this file if you'd like to avoid having to create your own autoloader.
+ *
+ * @package Requests
+ * @since   2.0.0
+ *
+ * @codeCoverageIgnore
+ */
+
+namespace WpOrg\Requests;
+
+/*
+ * Ensure the autoloader is only declared once.
+ * This safeguard is in place as this is the typical entry point for this library
+ * and this file being required unconditionally could easily cause
+ * fatal "Class already declared" errors.
+ */
+if (class_exists('WpOrg\Requests\Autoload') === false) {
+
+	/**
+	 * Autoloader for Requests for PHP.
+	 *
+	 * @package Requests
+	 */
+	class Autoload {
+
+		/**
+		 * List of the old PSR-0 class names in lowercase as keys with their PSR-4 case-sensitive name as a value.
+		 *
+		 * @var array
+		 */
+		private static $deprecated_classes = array(
+			// Interfaces.
+			'requests_auth'                              => '\WpOrg\Requests\Auth',
+			'requests_hooker'                            => '\WpOrg\Requests\Hooker',
+			'requests_proxy'                             => '\WpOrg\Requests\Proxy',
+			'requests_transport'                         => '\WpOrg\Requests\Transport',
+
+			// Classes.
+			'requests_cookie'                            => '\WpOrg\Requests\Cookie',
+			'requests_exception'                         => '\WpOrg\Requests\Exception',
+			'requests_hooks'                             => '\WpOrg\Requests\Hooks',
+			'requests_idnaencoder'                       => '\WpOrg\Requests\IdnaEncoder',
+			'requests_ipv6'                              => '\WpOrg\Requests\Ipv6',
+			'requests_iri'                               => '\WpOrg\Requests\Iri',
+			'requests_response'                          => '\WpOrg\Requests\Response',
+			'requests_session'                           => '\WpOrg\Requests\Session',
+			'requests_ssl'                               => '\WpOrg\Requests\Ssl',
+			'requests_auth_basic'                        => '\WpOrg\Requests\Auth\Basic',
+			'requests_cookie_jar'                        => '\WpOrg\Requests\Cookie\Jar',
+			'requests_proxy_http'                        => '\WpOrg\Requests\Proxy\Http',
+			'requests_response_headers'                  => '\WpOrg\Requests\Response\Headers',
+			'requests_transport_curl'                    => '\WpOrg\Requests\Transport\Curl',
+			'requests_transport_fsockopen'               => '\WpOrg\Requests\Transport\Fsockopen',
+			'requests_utility_caseinsensitivedictionary' => '\WpOrg\Requests\Utility\CaseInsensitiveDictionary',
+			'requests_utility_filterediterator'          => '\WpOrg\Requests\Utility\FilteredIterator',
+			'requests_exception_http'                    => '\WpOrg\Requests\Exception\Http',
+			'requests_exception_transport'               => '\WpOrg\Requests\Exception\Transport',
+			'requests_exception_transport_curl'          => '\WpOrg\Requests\Exception\Transport\Curl',
+			'requests_exception_http_304'                => '\WpOrg\Requests\Exception\Http\Status304',
+			'requests_exception_http_305'                => '\WpOrg\Requests\Exception\Http\Status305',
+			'requests_exception_http_306'                => '\WpOrg\Requests\Exception\Http\Status306',
+			'requests_exception_http_400'                => '\WpOrg\Requests\Exception\Http\Status400',
+			'requests_exception_http_401'                => '\WpOrg\Requests\Exception\Http\Status401',
+			'requests_exception_http_402'                => '\WpOrg\Requests\Exception\Http\Status402',
+			'requests_exception_http_403'                => '\WpOrg\Requests\Exception\Http\Status403',
+			'requests_exception_http_404'                => '\WpOrg\Requests\Exception\Http\Status404',
+			'requests_exception_http_405'                => '\WpOrg\Requests\Exception\Http\Status405',
+			'requests_exception_http_406'                => '\WpOrg\Requests\Exception\Http\Status406',
+			'requests_exception_http_407'                => '\WpOrg\Requests\Exception\Http\Status407',
+			'requests_exception_http_408'                => '\WpOrg\Requests\Exception\Http\Status408',
+			'requests_exception_http_409'                => '\WpOrg\Requests\Exception\Http\Status409',
+			'requests_exception_http_410'                => '\WpOrg\Requests\Exception\Http\Status410',
+			'requests_exception_http_411'                => '\WpOrg\Requests\Exception\Http\Status411',
+			'requests_exception_http_412'                => '\WpOrg\Requests\Exception\Http\Status412',
+			'requests_exception_http_413'                => '\WpOrg\Requests\Exception\Http\Status413',
+			'requests_exception_http_414'                => '\WpOrg\Requests\Exception\Http\Status414',
+			'requests_exception_http_415'                => '\WpOrg\Requests\Exception\Http\Status415',
+			'requests_exception_http_416'                => '\WpOrg\Requests\Exception\Http\Status416',
+			'requests_exception_http_417'                => '\WpOrg\Requests\Exception\Http\Status417',
+			'requests_exception_http_418'                => '\WpOrg\Requests\Exception\Http\Status418',
+			'requests_exception_http_428'                => '\WpOrg\Requests\Exception\Http\Status428',
+			'requests_exception_http_429'                => '\WpOrg\Requests\Exception\Http\Status429',
+			'requests_exception_http_431'                => '\WpOrg\Requests\Exception\Http\Status431',
+			'requests_exception_http_500'                => '\WpOrg\Requests\Exception\Http\Status500',
+			'requests_exception_http_501'                => '\WpOrg\Requests\Exception\Http\Status501',
+			'requests_exception_http_502'                => '\WpOrg\Requests\Exception\Http\Status502',
+			'requests_exception_http_503'                => '\WpOrg\Requests\Exception\Http\Status503',
+			'requests_exception_http_504'                => '\WpOrg\Requests\Exception\Http\Status504',
+			'requests_exception_http_505'                => '\WpOrg\Requests\Exception\Http\Status505',
+			'requests_exception_http_511'                => '\WpOrg\Requests\Exception\Http\Status511',
+			'requests_exception_http_unknown'            => '\WpOrg\Requests\Exception\Http\StatusUnknown',
+		);
+
+		/**
+		 * Register the autoloader.
+		 *
+		 * Note: the autoloader is *prepended* in the autoload queue.
+		 * This is done to ensure that the Requests 2.0 autoloader takes precedence
+		 * over a potentially (dependency-registered) Requests 1.x autoloader.
+		 *
+		 * @internal This method contains a safeguard against the autoloader being
+		 * registered multiple times. This safeguard uses a global constant to
+		 * (hopefully/in most cases) still function correctly, even if the
+		 * class would be renamed.
+		 *
+		 * @return void
+		 */
+		public static function register() {
+			if (defined('REQUESTS_AUTOLOAD_REGISTERED') === false) {
+				spl_autoload_register(array(self::class, 'load'), true);
+				define('REQUESTS_AUTOLOAD_REGISTERED', true);
+			}
+		}
+
+		/**
+		 * Autoloader.
+		 *
+		 * @param string $class_name Name of the class name to load.
+		 *
+		 * @return bool Whether a class was loaded or not.
+		 */
+		public static function load($class_name) {
+			// Check that the class starts with "Requests" (PSR-0) or "WpOrg\Requests" (PSR-4).
+			$psr_4_prefix_pos = stripos($class_name, 'WpOrg\\Requests\\');
+
+			if (stripos($class_name, 'Requests') !== 0 && $psr_4_prefix_pos !== 0) {
+				return false;
+			}
+
+			if ($class_name === 'Requests') {
+				// Reference to the original PSR-0 Requests class.
+				$file = dirname(__DIR__) . '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/library/Requests.php';
+			} elseif ($psr_4_prefix_pos === 0) {
+				// PSR-4 classname.
+				$file = __DIR__ . '/' . strtr(substr($class_name, 15), '\\', '/') . '.php';
+			}
+
+			if (isset($file) && file_exists($file)) {
+				include $file;
+				return true;
+			}
+
+			/*
+			 * Okay, so the class starts with "Requests", but we couldn't find the file.
+			 * If this is one of the deprecated/renamed PSR-0 classes being requested,
+			 * let's alias it to the new name and throw a deprecation notice.
+			 */
+			$class_lower = strtolower($class_name);
+
+			if (isset(self::$deprecated_classes[$class_lower])) {
+				/*
+				 * Integrators who cannot yet upgrade to the PSR-4 class names can silence deprecations
+				 * by defining a `REQUESTS_SILENCE_PSR0_DEPRECATIONS` constant and setting it to `true`.
+				 * The constant needs to be defined before the first deprecated class is requested
+				 * via this autoloader.
+				 */
+				if (!defined('REQUESTS_SILENCE_PSR0_DEPRECATIONS') || REQUESTS_SILENCE_PSR0_DEPRECATIONS !== true) {
+					// phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_trigger_error
+					trigger_error(
+						'The PSR-0 `Requests_...` class names in the Request library are deprecated.'
+						. ' Switch to the PSR-4 `WpOrg\Requests\...` class names at your earliest convenience.',
+						E_USER_DEPRECATED
+					);
+
+					// Prevent the deprecation notice from being thrown twice.
+					if (!defined('REQUESTS_SILENCE_PSR0_DEPRECATIONS')) {
+						define('REQUESTS_SILENCE_PSR0_DEPRECATIONS', true);
+					}
+				}
+
+				// Create an alias and let the autoloader recursively kick in to load the PSR-4 class.
+				return class_alias(self::$deprecated_classes[$class_lower], $class_name, true);
+			}
+
+			return false;
+		}
+	}
+}
diff --git a/library/Requests/Cookie.php b/src/Cookie.php
similarity index 92%
rename from library/Requests/Cookie.php
rename to src/Cookie.php
index d46956753..2e302ccef 100644
--- a/library/Requests/Cookie.php
+++ b/src/Cookie.php
@@ -6,13 +6,19 @@
  * @subpackage Cookies
  */
 
+namespace WpOrg\Requests;
+
+use WpOrg\Requests\Iri;
+use WpOrg\Requests\Response\Headers;
+use WpOrg\Requests\Utility\CaseInsensitiveDictionary;
+
 /**
  * Cookie storage object
  *
  * @package Requests
  * @subpackage Cookies
  */
-class Requests_Cookie {
+class Cookie {
 	/**
 	 * Cookie name.
 	 *
@@ -33,7 +39,7 @@ class Requests_Cookie {
 	 * Valid keys are (currently) path, domain, expires, max-age, secure and
 	 * httponly.
 	 *
-	 * @var Requests_Utility_CaseInsensitiveDictionary|array Array-like object
+	 * @var \WpOrg\Requests\Utility\CaseInsensitiveDictionary|array Array-like object
 	 */
 	public $attributes = array();
 
@@ -62,7 +68,7 @@ class Requests_Cookie {
 	 *
 	 * @param string $name
 	 * @param string $value
-	 * @param array|Requests_Utility_CaseInsensitiveDictionary $attributes Associative array of attribute data
+	 * @param array|\WpOrg\Requests\Utility\CaseInsensitiveDictionary $attributes Associative array of attribute data
 	 */
 	public function __construct($name, $value, $attributes = array(), $flags = array(), $reference_time = null) {
 		$this->name       = $name;
@@ -113,10 +119,10 @@ public function is_expired() {
 	/**
 	 * Check if a cookie is valid for a given URI
 	 *
-	 * @param Requests_IRI $uri URI to check
+	 * @param \WpOrg\Requests\Iri $uri URI to check
 	 * @return boolean Whether the cookie is valid for the given URI
 	 */
-	public function uri_matches(Requests_IRI $uri) {
+	public function uri_matches(Iri $uri) {
 		if (!$this->domain_matches($uri->host)) {
 			return false;
 		}
@@ -360,7 +366,7 @@ public function __toString() {
 	 * specifies some of this handling, but not in a thorough manner.
 	 *
 	 * @param string Cookie header value (from a Set-Cookie header)
-	 * @return Requests_Cookie Parsed cookie object
+	 * @return \WpOrg\Requests\Cookie Parsed cookie object
 	 */
 	public static function parse($string, $name = '', $reference_time = null) {
 		$parts   = explode(';', $string);
@@ -385,7 +391,7 @@ public static function parse($string, $name = '', $reference_time = null) {
 		$value = trim($value);
 
 		// Attribute key are handled case-insensitively
-		$attributes = new Requests_Utility_CaseInsensitiveDictionary();
+		$attributes = new CaseInsensitiveDictionary();
 
 		if (!empty($parts)) {
 			foreach ($parts as $part) {
@@ -403,18 +409,18 @@ public static function parse($string, $name = '', $reference_time = null) {
 			}
 		}
 
-		return new Requests_Cookie($name, $value, $attributes, array(), $reference_time);
+		return new static($name, $value, $attributes, array(), $reference_time);
 	}
 
 	/**
 	 * Parse all Set-Cookie headers from request headers
 	 *
-	 * @param Requests_Response_Headers $headers Headers to parse from
-	 * @param Requests_IRI|null $origin URI for comparing cookie origins
+	 * @param \WpOrg\Requests\Response\Headers $headers Headers to parse from
+	 * @param \WpOrg\Requests\Iri|null $origin URI for comparing cookie origins
 	 * @param int|null $time Reference time for expiration calculation
 	 * @return array
 	 */
-	public static function parse_from_headers(Requests_Response_Headers $headers, Requests_IRI $origin = null, $time = null) {
+	public static function parse_from_headers(Headers $headers, Iri $origin = null, $time = null) {
 		$cookie_headers = $headers->getValues('Set-Cookie');
 		if (empty($cookie_headers)) {
 			return array();
diff --git a/library/Requests/Cookie/Jar.php b/src/Cookie/Jar.php
similarity index 71%
rename from library/Requests/Cookie/Jar.php
rename to src/Cookie/Jar.php
index 9fee6b741..b33bf5c08 100644
--- a/library/Requests/Cookie/Jar.php
+++ b/src/Cookie/Jar.php
@@ -6,13 +6,25 @@
  * @subpackage Cookies
  */
 
+namespace WpOrg\Requests\Cookie;
+
+use ArrayAccess;
+use ArrayIterator;
+use IteratorAggregate;
+use ReturnTypeWillChange;
+use WpOrg\Requests\Cookie;
+use WpOrg\Requests\Exception;
+use WpOrg\Requests\Hooker;
+use WpOrg\Requests\Iri;
+use WpOrg\Requests\Response;
+
 /**
  * Cookie holder object
  *
  * @package Requests
  * @subpackage Cookies
  */
-class Requests_Cookie_Jar implements ArrayAccess, IteratorAggregate {
+class Jar implements ArrayAccess, IteratorAggregate {
 	/**
 	 * Actual item data
 	 *
@@ -30,17 +42,17 @@ public function __construct($cookies = array()) {
 	}
 
 	/**
-	 * Normalise cookie data into a Requests_Cookie
+	 * Normalise cookie data into a \WpOrg\Requests\Cookie
 	 *
-	 * @param string|Requests_Cookie $cookie
-	 * @return Requests_Cookie
+	 * @param string|\WpOrg\Requests\Cookie $cookie
+	 * @return \WpOrg\Requests\Cookie
 	 */
 	public function normalize_cookie($cookie, $key = null) {
-		if ($cookie instanceof Requests_Cookie) {
+		if ($cookie instanceof Cookie) {
 			return $cookie;
 		}
 
-		return Requests_Cookie::parse($cookie, $key);
+		return Cookie::parse($cookie, $key);
 	}
 
 	/**
@@ -72,7 +84,7 @@ public function offsetGet($key) {
 	/**
 	 * Set the given item
 	 *
-	 * @throws Requests_Exception On attempting to use dictionary as list (`invalidset`)
+	 * @throws \WpOrg\Requests\Exception On attempting to use dictionary as list (`invalidset`)
 	 *
 	 * @param string $key Item name
 	 * @param string $value Item value
@@ -80,7 +92,7 @@ public function offsetGet($key) {
 	#[ReturnTypeWillChange]
 	public function offsetSet($key, $value) {
 		if ($key === null) {
-			throw new Requests_Exception('Object is a dictionary, not a list', 'invalidset');
+			throw new Exception('Object is a dictionary, not a list', 'invalidset');
 		}
 
 		$this->cookies[$key] = $value;
@@ -99,7 +111,7 @@ public function offsetUnset($key) {
 	/**
 	 * Get an iterator for the data
 	 *
-	 * @return ArrayIterator
+	 * @return \ArrayIterator
 	 */
 	#[ReturnTypeWillChange]
 	public function getIterator() {
@@ -109,9 +121,9 @@ public function getIterator() {
 	/**
 	 * Register the cookie handler with the request's hooking system
 	 *
-	 * @param Requests_Hooker $hooks Hooking system
+	 * @param \WpOrg\Requests\Hooker $hooks Hooking system
 	 */
-	public function register(Requests_Hooker $hooks) {
+	public function register(Hooker $hooks) {
 		$hooks->register('requests.before_request', array($this, 'before_request'));
 		$hooks->register('requests.before_redirect_check', array($this, 'before_redirect_check'));
 	}
@@ -128,8 +140,8 @@ public function register(Requests_Hooker $hooks) {
 	 * @param array $options
 	 */
 	public function before_request($url, &$headers, &$data, &$type, &$options) {
-		if (!$url instanceof Requests_IRI) {
-			$url = new Requests_IRI($url);
+		if (!$url instanceof Iri) {
+			$url = new Iri($url);
 		}
 
 		if (!empty($this->cookies)) {
@@ -154,15 +166,15 @@ public function before_request($url, &$headers, &$data, &$type, &$options) {
 	/**
 	 * Parse all cookies from a response and attach them to the response
 	 *
-	 * @var Requests_Response $response
+	 * @var \WpOrg\Requests\Response $response
 	 */
-	public function before_redirect_check(Requests_Response $return) {
+	public function before_redirect_check(Response $return) {
 		$url = $return->url;
-		if (!$url instanceof Requests_IRI) {
-			$url = new Requests_IRI($url);
+		if (!$url instanceof Iri) {
+			$url = new Iri($url);
 		}
 
-		$cookies         = Requests_Cookie::parse_from_headers($return->headers, $url);
+		$cookies         = Cookie::parse_from_headers($return->headers, $url);
 		$this->cookies   = array_merge($this->cookies, $cookies);
 		$return->cookies = $this;
 	}
diff --git a/library/Requests/Exception.php b/src/Exception.php
similarity index 90%
rename from library/Requests/Exception.php
rename to src/Exception.php
index 1080efd97..543fcb6ab 100644
--- a/library/Requests/Exception.php
+++ b/src/Exception.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests;
+
+use Exception as PHPException;
+
 /**
  * Exception for HTTP requests
  *
  * @package Requests
  */
-class Requests_Exception extends Exception {
+class Exception extends PHPException {
 	/**
 	 * Type of exception
 	 *
diff --git a/library/Requests/Exception/HTTP.php b/src/Exception/Http.php
similarity index 81%
rename from library/Requests/Exception/HTTP.php
rename to src/Exception/Http.php
index be9388ef9..3f90e1557 100644
--- a/library/Requests/Exception/HTTP.php
+++ b/src/Exception/Http.php
@@ -5,12 +5,17 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception;
+
+use WpOrg\Requests\Exception;
+use WpOrg\Requests\Exception\Http\StatusUnknown;
+
 /**
  * Exception based on HTTP response
  *
  * @package Requests
  */
-class Requests_Exception_HTTP extends Requests_Exception {
+class Http extends Exception {
 	/**
 	 * HTTP status code
 	 *
@@ -58,14 +63,14 @@ public function getReason() {
 	 */
 	public static function get_class($code) {
 		if (!$code) {
-			return Requests_Exception_HTTP_Unknown::class;
+			return StatusUnknown::class;
 		}
 
-		$class = sprintf('Requests_Exception_HTTP_%d', $code);
+		$class = sprintf('\WpOrg\Requests\Exception\Http\Status%d', $code);
 		if (class_exists($class)) {
 			return $class;
 		}
 
-		return Requests_Exception_HTTP_Unknown::class;
+		return StatusUnknown::class;
 	}
 }
diff --git a/library/Requests/Exception/HTTP/304.php b/src/Exception/Http/Status304.php
similarity index 74%
rename from library/Requests/Exception/HTTP/304.php
rename to src/Exception/Http/Status304.php
index 2636ba451..d128678a4 100644
--- a/library/Requests/Exception/HTTP/304.php
+++ b/src/Exception/Http/Status304.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 304 Not Modified responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_304 extends Requests_Exception_HTTP {
+class Status304 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/305.php b/src/Exception/Http/Status305.php
similarity index 74%
rename from library/Requests/Exception/HTTP/305.php
rename to src/Exception/Http/Status305.php
index 37d115a81..9fc70a44c 100644
--- a/library/Requests/Exception/HTTP/305.php
+++ b/src/Exception/Http/Status305.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 305 Use Proxy responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_305 extends Requests_Exception_HTTP {
+class Status305 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/306.php b/src/Exception/Http/Status306.php
similarity index 74%
rename from library/Requests/Exception/HTTP/306.php
rename to src/Exception/Http/Status306.php
index 743a4ed1d..7fb03f0a8 100644
--- a/library/Requests/Exception/HTTP/306.php
+++ b/src/Exception/Http/Status306.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 306 Switch Proxy responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_306 extends Requests_Exception_HTTP {
+class Status306 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/400.php b/src/Exception/Http/Status400.php
similarity index 74%
rename from library/Requests/Exception/HTTP/400.php
rename to src/Exception/Http/Status400.php
index 5bd5428c0..f9b799ba2 100644
--- a/library/Requests/Exception/HTTP/400.php
+++ b/src/Exception/Http/Status400.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 400 Bad Request responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_400 extends Requests_Exception_HTTP {
+class Status400 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/401.php b/src/Exception/Http/Status401.php
similarity index 74%
rename from library/Requests/Exception/HTTP/401.php
rename to src/Exception/Http/Status401.php
index 62a283ab0..b991c8bc2 100644
--- a/library/Requests/Exception/HTTP/401.php
+++ b/src/Exception/Http/Status401.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 401 Unauthorized responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_401 extends Requests_Exception_HTTP {
+class Status401 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/402.php b/src/Exception/Http/Status402.php
similarity index 75%
rename from library/Requests/Exception/HTTP/402.php
rename to src/Exception/Http/Status402.php
index f287fd4b2..eaf6ef8de 100644
--- a/library/Requests/Exception/HTTP/402.php
+++ b/src/Exception/Http/Status402.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 402 Payment Required responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_402 extends Requests_Exception_HTTP {
+class Status402 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/403.php b/src/Exception/Http/Status403.php
similarity index 74%
rename from library/Requests/Exception/HTTP/403.php
rename to src/Exception/Http/Status403.php
index 2ae1c4445..b4e6706dc 100644
--- a/library/Requests/Exception/HTTP/403.php
+++ b/src/Exception/Http/Status403.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 403 Forbidden responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_403 extends Requests_Exception_HTTP {
+class Status403 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/404.php b/src/Exception/Http/Status404.php
similarity index 74%
rename from library/Requests/Exception/HTTP/404.php
rename to src/Exception/Http/Status404.php
index e6e28672c..48b936233 100644
--- a/library/Requests/Exception/HTTP/404.php
+++ b/src/Exception/Http/Status404.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 404 Not Found responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_404 extends Requests_Exception_HTTP {
+class Status404 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/405.php b/src/Exception/Http/Status405.php
similarity index 75%
rename from library/Requests/Exception/HTTP/405.php
rename to src/Exception/Http/Status405.php
index 0461e6108..680d64a4f 100644
--- a/library/Requests/Exception/HTTP/405.php
+++ b/src/Exception/Http/Status405.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 405 Method Not Allowed responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_405 extends Requests_Exception_HTTP {
+class Status405 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/406.php b/src/Exception/Http/Status406.php
similarity index 75%
rename from library/Requests/Exception/HTTP/406.php
rename to src/Exception/Http/Status406.php
index 980ef0efc..60e5302e0 100644
--- a/library/Requests/Exception/HTTP/406.php
+++ b/src/Exception/Http/Status406.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 406 Not Acceptable responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_406 extends Requests_Exception_HTTP {
+class Status406 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/407.php b/src/Exception/Http/Status407.php
similarity index 77%
rename from library/Requests/Exception/HTTP/407.php
rename to src/Exception/Http/Status407.php
index d08c6af7c..7911c87a2 100644
--- a/library/Requests/Exception/HTTP/407.php
+++ b/src/Exception/Http/Status407.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 407 Proxy Authentication Required responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_407 extends Requests_Exception_HTTP {
+class Status407 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/408.php b/src/Exception/Http/Status408.php
similarity index 75%
rename from library/Requests/Exception/HTTP/408.php
rename to src/Exception/Http/Status408.php
index db15bc291..bff63610e 100644
--- a/library/Requests/Exception/HTTP/408.php
+++ b/src/Exception/Http/Status408.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 408 Request Timeout responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_408 extends Requests_Exception_HTTP {
+class Status408 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/409.php b/src/Exception/Http/Status409.php
similarity index 74%
rename from library/Requests/Exception/HTTP/409.php
rename to src/Exception/Http/Status409.php
index 83002f936..db41d6c6e 100644
--- a/library/Requests/Exception/HTTP/409.php
+++ b/src/Exception/Http/Status409.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 409 Conflict responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_409 extends Requests_Exception_HTTP {
+class Status409 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/410.php b/src/Exception/Http/Status410.php
similarity index 73%
rename from library/Requests/Exception/HTTP/410.php
rename to src/Exception/Http/Status410.php
index 5bf7aa6d4..0bd4b28b9 100644
--- a/library/Requests/Exception/HTTP/410.php
+++ b/src/Exception/Http/Status410.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 410 Gone responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_410 extends Requests_Exception_HTTP {
+class Status410 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/411.php b/src/Exception/Http/Status411.php
similarity index 75%
rename from library/Requests/Exception/HTTP/411.php
rename to src/Exception/Http/Status411.php
index 25517b4f3..037edccba 100644
--- a/library/Requests/Exception/HTTP/411.php
+++ b/src/Exception/Http/Status411.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 411 Length Required responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_411 extends Requests_Exception_HTTP {
+class Status411 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/412.php b/src/Exception/Http/Status412.php
similarity index 75%
rename from library/Requests/Exception/HTTP/412.php
rename to src/Exception/Http/Status412.php
index e89533a7e..12cf8574e 100644
--- a/library/Requests/Exception/HTTP/412.php
+++ b/src/Exception/Http/Status412.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 412 Precondition Failed responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_412 extends Requests_Exception_HTTP {
+class Status412 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/413.php b/src/Exception/Http/Status413.php
similarity index 76%
rename from library/Requests/Exception/HTTP/413.php
rename to src/Exception/Http/Status413.php
index a7b38fce1..a6d40474c 100644
--- a/library/Requests/Exception/HTTP/413.php
+++ b/src/Exception/Http/Status413.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 413 Request Entity Too Large responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_413 extends Requests_Exception_HTTP {
+class Status413 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/414.php b/src/Exception/Http/Status414.php
similarity index 76%
rename from library/Requests/Exception/HTTP/414.php
rename to src/Exception/Http/Status414.php
index 54c8b8c9a..8e4a6d7ee 100644
--- a/library/Requests/Exception/HTTP/414.php
+++ b/src/Exception/Http/Status414.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 414 Request-URI Too Large responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_414 extends Requests_Exception_HTTP {
+class Status414 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/415.php b/src/Exception/Http/Status415.php
similarity index 76%
rename from library/Requests/Exception/HTTP/415.php
rename to src/Exception/Http/Status415.php
index 6b5f0785b..713c59192 100644
--- a/library/Requests/Exception/HTTP/415.php
+++ b/src/Exception/Http/Status415.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 415 Unsupported Media Type responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_415 extends Requests_Exception_HTTP {
+class Status415 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/416.php b/src/Exception/Http/Status416.php
similarity index 77%
rename from library/Requests/Exception/HTTP/416.php
rename to src/Exception/Http/Status416.php
index 48a4ecdb8..db27f24b9 100644
--- a/library/Requests/Exception/HTTP/416.php
+++ b/src/Exception/Http/Status416.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 416 Requested Range Not Satisfiable responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_416 extends Requests_Exception_HTTP {
+class Status416 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/417.php b/src/Exception/Http/Status417.php
similarity index 75%
rename from library/Requests/Exception/HTTP/417.php
rename to src/Exception/Http/Status417.php
index 81570330a..9e1fce484 100644
--- a/library/Requests/Exception/HTTP/417.php
+++ b/src/Exception/Http/Status417.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 417 Expectation Failed responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_417 extends Requests_Exception_HTTP {
+class Status417 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/418.php b/src/Exception/Http/Status418.php
similarity index 79%
rename from library/Requests/Exception/HTTP/418.php
rename to src/Exception/Http/Status418.php
index 0fcc87d61..f98055fe6 100644
--- a/library/Requests/Exception/HTTP/418.php
+++ b/src/Exception/Http/Status418.php
@@ -6,13 +6,17 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 418 I'm A Teapot responses
  *
  * @see https://tools.ietf.org/html/rfc2324
  * @package Requests
  */
-class Requests_Exception_HTTP_418 extends Requests_Exception_HTTP {
+class Status418 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/428.php b/src/Exception/Http/Status428.php
similarity index 80%
rename from library/Requests/Exception/HTTP/428.php
rename to src/Exception/Http/Status428.php
index 799ddffd5..8638c1e17 100644
--- a/library/Requests/Exception/HTTP/428.php
+++ b/src/Exception/Http/Status428.php
@@ -6,13 +6,17 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 428 Precondition Required responses
  *
  * @see https://tools.ietf.org/html/rfc6585
  * @package Requests
  */
-class Requests_Exception_HTTP_428 extends Requests_Exception_HTTP {
+class Status428 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/429.php b/src/Exception/Http/Status429.php
similarity index 81%
rename from library/Requests/Exception/HTTP/429.php
rename to src/Exception/Http/Status429.php
index 78a3148ad..5d35f062b 100644
--- a/library/Requests/Exception/HTTP/429.php
+++ b/src/Exception/Http/Status429.php
@@ -6,13 +6,17 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 429 Too Many Requests responses
  *
  * @see https://tools.ietf.org/html/draft-nottingham-http-new-status-04
  * @package Requests
  */
-class Requests_Exception_HTTP_429 extends Requests_Exception_HTTP {
+class Status429 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/431.php b/src/Exception/Http/Status431.php
similarity index 81%
rename from library/Requests/Exception/HTTP/431.php
rename to src/Exception/Http/Status431.php
index a92b48a4e..4eebd55fa 100644
--- a/library/Requests/Exception/HTTP/431.php
+++ b/src/Exception/Http/Status431.php
@@ -6,13 +6,17 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 431 Request Header Fields Too Large responses
  *
  * @see https://tools.ietf.org/html/rfc6585
  * @package Requests
  */
-class Requests_Exception_HTTP_431 extends Requests_Exception_HTTP {
+class Status431 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/500.php b/src/Exception/Http/Status500.php
similarity index 76%
rename from library/Requests/Exception/HTTP/500.php
rename to src/Exception/Http/Status500.php
index 22a6406ab..8e12e5fc3 100644
--- a/library/Requests/Exception/HTTP/500.php
+++ b/src/Exception/Http/Status500.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 500 Internal Server Error responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_500 extends Requests_Exception_HTTP {
+class Status500 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/501.php b/src/Exception/Http/Status501.php
similarity index 75%
rename from library/Requests/Exception/HTTP/501.php
rename to src/Exception/Http/Status501.php
index 11f395b20..89fe4a43b 100644
--- a/library/Requests/Exception/HTTP/501.php
+++ b/src/Exception/Http/Status501.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 501 Not Implemented responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_501 extends Requests_Exception_HTTP {
+class Status501 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/502.php b/src/Exception/Http/Status502.php
similarity index 74%
rename from library/Requests/Exception/HTTP/502.php
rename to src/Exception/Http/Status502.php
index 43f576a62..c4fb85e60 100644
--- a/library/Requests/Exception/HTTP/502.php
+++ b/src/Exception/Http/Status502.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 502 Bad Gateway responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_502 extends Requests_Exception_HTTP {
+class Status502 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/503.php b/src/Exception/Http/Status503.php
similarity index 75%
rename from library/Requests/Exception/HTTP/503.php
rename to src/Exception/Http/Status503.php
index 4024a4f5c..264264189 100644
--- a/library/Requests/Exception/HTTP/503.php
+++ b/src/Exception/Http/Status503.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 503 Service Unavailable responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_503 extends Requests_Exception_HTTP {
+class Status503 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/504.php b/src/Exception/Http/Status504.php
similarity index 75%
rename from library/Requests/Exception/HTTP/504.php
rename to src/Exception/Http/Status504.php
index 25fd08631..3c484febc 100644
--- a/library/Requests/Exception/HTTP/504.php
+++ b/src/Exception/Http/Status504.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 504 Gateway Timeout responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_504 extends Requests_Exception_HTTP {
+class Status504 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/505.php b/src/Exception/Http/Status505.php
similarity index 77%
rename from library/Requests/Exception/HTTP/505.php
rename to src/Exception/Http/Status505.php
index 1f7cfec9b..53e0489ee 100644
--- a/library/Requests/Exception/HTTP/505.php
+++ b/src/Exception/Http/Status505.php
@@ -5,12 +5,16 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 505 HTTP Version Not Supported responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_505 extends Requests_Exception_HTTP {
+class Status505 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/511.php b/src/Exception/Http/Status511.php
similarity index 81%
rename from library/Requests/Exception/HTTP/511.php
rename to src/Exception/Http/Status511.php
index 3332513b1..6149bd9a8 100644
--- a/library/Requests/Exception/HTTP/511.php
+++ b/src/Exception/Http/Status511.php
@@ -6,13 +6,17 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+
 /**
  * Exception for 511 Network Authentication Required responses
  *
  * @see https://tools.ietf.org/html/rfc6585
  * @package Requests
  */
-class Requests_Exception_HTTP_511 extends Requests_Exception_HTTP {
+class Status511 extends Http {
 	/**
 	 * HTTP status code
 	 *
diff --git a/library/Requests/Exception/HTTP/Unknown.php b/src/Exception/Http/StatusUnknown.php
similarity index 72%
rename from library/Requests/Exception/HTTP/Unknown.php
rename to src/Exception/Http/StatusUnknown.php
index b7eeb7953..02e129665 100644
--- a/library/Requests/Exception/HTTP/Unknown.php
+++ b/src/Exception/Http/StatusUnknown.php
@@ -5,12 +5,17 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Exception\Http;
+
+use WpOrg\Requests\Exception\Http;
+use WpOrg\Requests\Response;
+
 /**
  * Exception for unknown status responses
  *
  * @package Requests
  */
-class Requests_Exception_HTTP_Unknown extends Requests_Exception_HTTP {
+class StatusUnknown extends Http {
 	/**
 	 * HTTP status code
 	 *
@@ -28,14 +33,14 @@ class Requests_Exception_HTTP_Unknown extends Requests_Exception_HTTP {
 	/**
 	 * Create a new exception
 	 *
-	 * If `$data` is an instance of {@see Requests_Response}, uses the status
+	 * If `$data` is an instance of {@see \WpOrg\Requests\Response}, uses the status
 	 * code from it. Otherwise, sets as 0
 	 *
 	 * @param string|null $reason Reason phrase
 	 * @param mixed $data Associated data
 	 */
 	public function __construct($reason = null, $data = null) {
-		if ($data instanceof Requests_Response) {
+		if ($data instanceof Response) {
 			$this->code = $data->status_code;
 		}
 
diff --git a/src/Exception/InvalidArgument.php b/src/Exception/InvalidArgument.php
new file mode 100644
index 000000000..a1d4c2ada
--- /dev/null
+++ b/src/Exception/InvalidArgument.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace WpOrg\Requests\Exception;
+
+use InvalidArgumentException;
+
+/**
+ * Exception for an invalid argument passed.
+ *
+ * @package Requests
+ * @since   2.0.0
+ */
+class InvalidArgument extends InvalidArgumentException {}
diff --git a/src/Exception/Transport.php b/src/Exception/Transport.php
new file mode 100644
index 000000000..5b112507e
--- /dev/null
+++ b/src/Exception/Transport.php
@@ -0,0 +1,7 @@
+<?php
+
+namespace WpOrg\Requests\Exception;
+
+use WpOrg\Requests\Exception;
+
+class Transport extends Exception {}
diff --git a/library/Requests/Exception/Transport/cURL.php b/src/Exception/Transport/Curl.php
similarity index 87%
rename from library/Requests/Exception/Transport/cURL.php
rename to src/Exception/Transport/Curl.php
index fffa8c259..d99a3fe35 100644
--- a/library/Requests/Exception/Transport/cURL.php
+++ b/src/Exception/Transport/Curl.php
@@ -1,6 +1,10 @@
 <?php
 
-class Requests_Exception_Transport_cURL extends Requests_Exception_Transport {
+namespace WpOrg\Requests\Exception\Transport;
+
+use WpOrg\Requests\Exception\Transport;
+
+class Curl extends Transport {
 
 	const EASY  = 'cURLEasy';
 	const MULTI = 'cURLMulti';
diff --git a/library/Requests/Hooker.php b/src/Hooker.php
similarity index 93%
rename from library/Requests/Hooker.php
rename to src/Hooker.php
index c852931f1..2ef5dd1ab 100644
--- a/library/Requests/Hooker.php
+++ b/src/Hooker.php
@@ -6,13 +6,15 @@
  * @subpackage Utilities
  */
 
+namespace WpOrg\Requests;
+
 /**
  * Event dispatcher
  *
  * @package Requests
  * @subpackage Utilities
  */
-interface Requests_Hooker {
+interface Hooker {
 	/**
 	 * Register a callback for a hook
 	 *
diff --git a/library/Requests/Hooks.php b/src/Hooks.php
similarity index 93%
rename from library/Requests/Hooks.php
rename to src/Hooks.php
index 2a5111b56..86d5b22ca 100644
--- a/library/Requests/Hooks.php
+++ b/src/Hooks.php
@@ -6,13 +6,17 @@
  * @subpackage Utilities
  */
 
+namespace WpOrg\Requests;
+
+use WpOrg\Requests\Hooker;
+
 /**
  * Handles adding and dispatching events
  *
  * @package Requests
  * @subpackage Utilities
  */
-class Requests_Hooks implements Requests_Hooker {
+class Hooks implements Hooker {
 	/**
 	 * Registered callbacks for each hook
 	 *
diff --git a/library/Requests/IDNAEncoder.php b/src/IdnaEncoder.php
similarity index 84%
rename from library/Requests/IDNAEncoder.php
rename to src/IdnaEncoder.php
index 881142935..9a4751f53 100644
--- a/library/Requests/IDNAEncoder.php
+++ b/src/IdnaEncoder.php
@@ -1,5 +1,9 @@
 <?php
 
+namespace WpOrg\Requests;
+
+use WpOrg\Requests\Exception;
+
 /**
  * IDNA URL encoder
  *
@@ -10,7 +14,7 @@
  * @see https://tools.ietf.org/html/rfc3490 IDNA specification
  * @see https://tools.ietf.org/html/rfc3492 Punycode/Bootstrap specification
  */
-class Requests_IDNAEncoder {
+class IdnaEncoder {
 	/**
 	 * ACE prefix used for IDNA
 	 *
@@ -51,10 +55,10 @@ public static function encode($string) {
 	/**
 	 * Convert a UTF-8 string to an ASCII string using Punycode
 	 *
-	 * @throws Requests_Exception Provided string longer than 64 ASCII characters (`idna.provided_too_long`)
-	 * @throws Requests_Exception Prepared string longer than 64 ASCII characters (`idna.prepared_too_long`)
-	 * @throws Requests_Exception Provided string already begins with xn-- (`idna.provided_is_prefixed`)
-	 * @throws Requests_Exception Encoded string longer than 64 ASCII characters (`idna.encoded_too_long`)
+	 * @throws \WpOrg\Requests\Exception Provided string longer than 64 ASCII characters (`idna.provided_too_long`)
+	 * @throws \WpOrg\Requests\Exception Prepared string longer than 64 ASCII characters (`idna.prepared_too_long`)
+	 * @throws \WpOrg\Requests\Exception Provided string already begins with xn-- (`idna.provided_is_prefixed`)
+	 * @throws \WpOrg\Requests\Exception Encoded string longer than 64 ASCII characters (`idna.encoded_too_long`)
 	 *
 	 * @param string $string ASCII or UTF-8 string (max length 64 characters)
 	 * @return string ASCII string
@@ -67,7 +71,7 @@ public static function to_ascii($string) {
 				return $string;
 			}
 
-			throw new Requests_Exception('Provided string is too long', 'idna.provided_too_long', $string);
+			throw new Exception('Provided string is too long', 'idna.provided_too_long', $string);
 		}
 
 		// Step 2: nameprep
@@ -81,12 +85,12 @@ public static function to_ascii($string) {
 				return $string;
 			}
 
-			throw new Requests_Exception('Prepared string is too long', 'idna.prepared_too_long', $string);
+			throw new Exception('Prepared string is too long', 'idna.prepared_too_long', $string);
 		}
 
 		// Step 5: Check ACE prefix
 		if (strpos($string, self::ACE_PREFIX) === 0) {
-			throw new Requests_Exception('Provided string begins with ACE prefix', 'idna.provided_is_prefixed', $string);
+			throw new Exception('Provided string begins with ACE prefix', 'idna.provided_is_prefixed', $string);
 		}
 
 		// Step 6: Encode with Punycode
@@ -100,7 +104,7 @@ public static function to_ascii($string) {
 			return $string;
 		}
 
-		throw new Requests_Exception('Encoded string is too long', 'idna.encoded_too_long', $string);
+		throw new Exception('Encoded string is too long', 'idna.encoded_too_long', $string);
 	}
 
 	/**
@@ -129,9 +133,9 @@ protected static function nameprep($string) {
 	/**
 	 * Convert a UTF-8 string to a UCS-4 codepoint array
 	 *
-	 * Based on Requests_IRI::replace_invalid_with_pct_encoding()
+	 * Based on \WpOrg\Requests\Iri::replace_invalid_with_pct_encoding()
 	 *
-	 * @throws Requests_Exception Invalid UTF-8 codepoint (`idna.invalidcodepoint`)
+	 * @throws \WpOrg\Requests\Exception Invalid UTF-8 codepoint (`idna.invalidcodepoint`)
 	 * @param string $input
 	 * @return array Unicode code points
 	 */
@@ -171,19 +175,19 @@ protected static function utf8_to_codepoints($input) {
 			}
 			// Invalid byte:
 			else {
-				throw new Requests_Exception('Invalid Unicode codepoint', 'idna.invalidcodepoint', $value);
+				throw new Exception('Invalid Unicode codepoint', 'idna.invalidcodepoint', $value);
 			}
 
 			if ($remaining > 0) {
 				if ($position + $length > $strlen) {
-					throw new Requests_Exception('Invalid Unicode codepoint', 'idna.invalidcodepoint', $character);
+					throw new Exception('Invalid Unicode codepoint', 'idna.invalidcodepoint', $character);
 				}
 				for ($position++; $remaining > 0; $position++) {
 					$value = ord($input[$position]);
 
 					// If it is invalid, count the sequence as invalid and reprocess the current byte:
 					if (($value & 0xC0) !== 0x80) {
-						throw new Requests_Exception('Invalid Unicode codepoint', 'idna.invalidcodepoint', $character);
+						throw new Exception('Invalid Unicode codepoint', 'idna.invalidcodepoint', $character);
 					}
 
 					--$remaining;
@@ -208,7 +212,7 @@ protected static function utf8_to_codepoints($input) {
 					|| $character > 0xEFFFD
 				)
 			) {
-				throw new Requests_Exception('Invalid Unicode codepoint', 'idna.invalidcodepoint', $character);
+				throw new Exception('Invalid Unicode codepoint', 'idna.invalidcodepoint', $character);
 			}
 
 			$codepoints[] = $character;
@@ -221,7 +225,7 @@ protected static function utf8_to_codepoints($input) {
 	 * RFC3492-compliant encoder
 	 *
 	 * @internal Pseudo-code from Section 6.3 is commented with "#" next to relevant code
-	 * @throws Requests_Exception On character outside of the domain (never happens with Punycode) (`idna.character_outside_domain`)
+	 * @throws \WpOrg\Requests\Exception On character outside of the domain (never happens with Punycode) (`idna.character_outside_domain`)
 	 *
 	 * @param string $input UTF-8 encoded string to encode
 	 * @return string Punycode-encoded string
@@ -252,7 +256,7 @@ public static function punycode_encode($input) {
 			// This never occurs for Punycode, so ignore in coverage
 			// @codeCoverageIgnoreStart
 			elseif ($char < $n) {
-				throw new Requests_Exception('Invalid character', 'idna.character_outside_domain', $char);
+				throw new Exception('Invalid character', 'idna.character_outside_domain', $char);
 			}
 			// @codeCoverageIgnoreEnd
 			else {
@@ -333,7 +337,7 @@ public static function punycode_encode($input) {
 	 * Convert a digit to its respective character
 	 *
 	 * @see https://tools.ietf.org/html/rfc3492#section-5
-	 * @throws Requests_Exception On invalid digit (`idna.invalid_digit`)
+	 * @throws \WpOrg\Requests\Exception On invalid digit (`idna.invalid_digit`)
 	 *
 	 * @param int $digit Digit in the range 0-35
 	 * @return string Single character corresponding to digit
@@ -342,7 +346,7 @@ protected static function digit_to_char($digit) {
 		// @codeCoverageIgnoreStart
 		// As far as I know, this never happens, but still good to be sure.
 		if ($digit < 0 || $digit > 35) {
-			throw new Requests_Exception(sprintf('Invalid digit %d', $digit), 'idna.invalid_digit', $digit);
+			throw new Exception(sprintf('Invalid digit %d', $digit), 'idna.invalid_digit', $digit);
 		}
 		// @codeCoverageIgnoreEnd
 		$digits = 'abcdefghijklmnopqrstuvwxyz0123456789';
diff --git a/library/Requests/IPv6.php b/src/Ipv6.php
similarity index 99%
rename from library/Requests/IPv6.php
rename to src/Ipv6.php
index 41ab89cca..83e6f2aec 100644
--- a/library/Requests/IPv6.php
+++ b/src/Ipv6.php
@@ -6,6 +6,8 @@
  * @subpackage Utilities
  */
 
+namespace WpOrg\Requests;
+
 /**
  * Class to validate and to work with IPv6 addresses
  *
@@ -15,7 +17,7 @@
  * @package Requests
  * @subpackage Utilities
  */
-class Requests_IPv6 {
+class Ipv6 {
 	/**
 	 * Uncompresses an IPv6 address
 	 *
diff --git a/library/Requests/IRI.php b/src/Iri.php
similarity index 97%
rename from library/Requests/IRI.php
rename to src/Iri.php
index 749b0bcf5..a52fb20e1 100644
--- a/library/Requests/IRI.php
+++ b/src/Iri.php
@@ -6,6 +6,11 @@
  * @subpackage Utilities
  */
 
+namespace WpOrg\Requests;
+
+use WpOrg\Requests\Exception;
+use WpOrg\Requests\Ipv6;
+
 /**
  * IRI parser/serialiser/normaliser
  *
@@ -63,7 +68,7 @@
  * @property string $fragment Fragment, formatted for a URI (after '#')
  * @property string $ifragment Fragment part of the IRI (after '#')
  */
-class Requests_IRI {
+class Iri {
 	/**
 	 * Scheme
 	 *
@@ -251,13 +256,13 @@ public function __construct($iri = null) {
 	 *
 	 * Returns false if $base is not absolute, otherwise an IRI.
 	 *
-	 * @param Requests_IRI|string $base (Absolute) Base IRI
-	 * @param Requests_IRI|string $relative Relative IRI
-	 * @return Requests_IRI|false
+	 * @param \WpOrg\Requests\Iri|string $base (Absolute) Base IRI
+	 * @param \WpOrg\Requests\Iri|string $relative Relative IRI
+	 * @return \WpOrg\Requests\Iri|false
 	 */
 	public static function absolutize($base, $relative) {
-		if (!($relative instanceof Requests_IRI)) {
-			$relative = new Requests_IRI($relative);
+		if (!($relative instanceof self)) {
+			$relative = new self($relative);
 		}
 		if (!$relative->is_valid()) {
 			return false;
@@ -266,8 +271,8 @@ public static function absolutize($base, $relative) {
 			return clone $relative;
 		}
 
-		if (!($base instanceof Requests_IRI)) {
-			$base = new Requests_IRI($base);
+		if (!($base instanceof self)) {
+			$base = new self($base);
 		}
 		if ($base->scheme === null || !$base->is_valid()) {
 			return false;
@@ -279,7 +284,7 @@ public static function absolutize($base, $relative) {
 				$target->scheme = $base->scheme;
 			}
 			else {
-				$target = new Requests_IRI;
+				$target = new self;
 				$target->scheme = $base->scheme;
 				$target->iuserinfo = $base->iuserinfo;
 				$target->ihost = $base->ihost;
@@ -330,7 +335,7 @@ protected function parse_iri($iri) {
 		$iri = trim($iri, "\x20\x09\x0A\x0C\x0D");
 		$has_match = preg_match('/^((?P<scheme>[^:\/?#]+):)?(\/\/(?P<authority>[^\/?#]*))?(?P<path>[^?#]*)(\?(?P<query>[^#]*))?(#(?P<fragment>.*))?$/', $iri, $match);
 		if (!$has_match) {
-			throw new Requests_Exception('Cannot parse supplied IRI', 'iri.cannot_parse', $iri);
+			throw new Exception('Cannot parse supplied IRI', 'iri.cannot_parse', $iri);
 		}
 
 		if ($match[1] === '') {
@@ -863,8 +868,8 @@ protected function set_host($ihost) {
 			return true;
 		}
 		if (substr($ihost, 0, 1) === '[' && substr($ihost, -1) === ']') {
-			if (Requests_IPv6::check_ipv6(substr($ihost, 1, -1))) {
-				$this->ihost = '[' . Requests_IPv6::compress(substr($ihost, 1, -1)) . ']';
+			if (Ipv6::check_ipv6(substr($ihost, 1, -1))) {
+				$this->ihost = '[' . Ipv6::compress(substr($ihost, 1, -1)) . ']';
 			}
 			else {
 				$this->ihost = null;
diff --git a/library/Requests/Proxy.php b/src/Proxy.php
similarity index 54%
rename from library/Requests/Proxy.php
rename to src/Proxy.php
index 0a798dbe9..d7ca0148d 100644
--- a/library/Requests/Proxy.php
+++ b/src/Proxy.php
@@ -7,6 +7,10 @@
  * @since 1.6
  */
 
+namespace WpOrg\Requests;
+
+use WpOrg\Requests\Hooks;
+
 /**
  * Proxy connection interface
  *
@@ -15,21 +19,21 @@
  * Parameters should be passed via the constructor where possible, as this
  * makes it much easier for users to use your provider.
  *
- * @see Requests_Hooks
+ * @see \WpOrg\Requests\Hooks
  * @package Requests
  * @subpackage Proxy
  * @since 1.6
  */
-interface Requests_Proxy {
+interface Proxy {
 	/**
 	 * Register hooks as needed
 	 *
-	 * This method is called in {@see Requests::request} when the user has set
-	 * an instance as the 'auth' option. Use this callback to register all the
+	 * This method is called in {@see \WpOrg\Requests\Requests::request} when the user
+	 * has set an instance as the 'auth' option. Use this callback to register all the
 	 * hooks you'll need.
 	 *
-	 * @see Requests_Hooks::register
-	 * @param Requests_Hooks $hooks Hook system
+	 * @see \WpOrg\Requests\Hooks::register
+	 * @param \WpOrg\Requests\Hooks $hooks Hook system
 	 */
-	public function register(Requests_Hooks $hooks);
+	public function register(Hooks $hooks);
 }
diff --git a/library/Requests/Proxy/HTTP.php b/src/Proxy/Http.php
similarity index 88%
rename from library/Requests/Proxy/HTTP.php
rename to src/Proxy/Http.php
index 25bb95a94..330342a6f 100644
--- a/library/Requests/Proxy/HTTP.php
+++ b/src/Proxy/Http.php
@@ -7,6 +7,12 @@
  * @since 1.6
  */
 
+namespace WpOrg\Requests\Proxy;
+
+use WpOrg\Requests\Exception;
+use WpOrg\Requests\Hooks;
+use WpOrg\Requests\Proxy;
+
 /**
  * HTTP Proxy connection interface
  *
@@ -16,7 +22,7 @@
  * @subpackage Proxy
  * @since 1.6
  */
-class Requests_Proxy_HTTP implements Requests_Proxy {
+class Http implements Proxy {
 	/**
 	 * Proxy host and port
 	 *
@@ -51,7 +57,7 @@ class Requests_Proxy_HTTP implements Requests_Proxy {
 	 * Constructor
 	 *
 	 * @since 1.6
-	 * @throws Requests_Exception On incorrect number of arguments (`authbasicbadargs`)
+	 * @throws \WpOrg\Requests\Exception On incorrect number of arguments (`authbasicbadargs`)
 	 * @param array|null $args Array of user and password. Must have exactly two elements
 	 */
 	public function __construct($args = null) {
@@ -67,7 +73,7 @@ public function __construct($args = null) {
 				$this->use_authentication                    = true;
 			}
 			else {
-				throw new Requests_Exception('Invalid number of arguments', 'proxyhttpbadargs');
+				throw new Exception('Invalid number of arguments', 'proxyhttpbadargs');
 			}
 		}
 	}
@@ -80,9 +86,9 @@ public function __construct($args = null) {
 	 * @see fsockopen_remote_socket
 	 * @see fsockopen_remote_host_path
 	 * @see fsockopen_header
-	 * @param Requests_Hooks $hooks Hook system
+	 * @param \WpOrg\Requests\Hooks $hooks Hook system
 	 */
-	public function register(Requests_Hooks $hooks) {
+	public function register(Hooks $hooks) {
 		$hooks->register('curl.before_send', array($this, 'curl_before_send'));
 
 		$hooks->register('fsockopen.remote_socket', array($this, 'fsockopen_remote_socket'));
diff --git a/src/Requests.php b/src/Requests.php
new file mode 100644
index 000000000..19d52689d
--- /dev/null
+++ b/src/Requests.php
@@ -0,0 +1,968 @@
+<?php
+/**
+ * Requests for PHP
+ *
+ * Inspired by Requests for Python.
+ *
+ * Based on concepts from SimplePie_File, RequestCore and WP_Http.
+ *
+ * @package Requests
+ */
+
+namespace WpOrg\Requests;
+
+use WpOrg\Requests\Auth\Basic;
+use WpOrg\Requests\Cookie\Jar;
+use WpOrg\Requests\Exception;
+use WpOrg\Requests\Hooks;
+use WpOrg\Requests\IdnaEncoder;
+use WpOrg\Requests\Iri;
+use WpOrg\Requests\Proxy\Http;
+use WpOrg\Requests\Response;
+use WpOrg\Requests\Transport\Curl;
+use WpOrg\Requests\Transport\Fsockopen;
+
+/**
+ * Requests for PHP
+ *
+ * Inspired by Requests for Python.
+ *
+ * Based on concepts from SimplePie_File, RequestCore and WP_Http.
+ *
+ * @package Requests
+ */
+class Requests {
+	/**
+	 * POST method
+	 *
+	 * @var string
+	 */
+	const POST = 'POST';
+
+	/**
+	 * PUT method
+	 *
+	 * @var string
+	 */
+	const PUT = 'PUT';
+
+	/**
+	 * GET method
+	 *
+	 * @var string
+	 */
+	const GET = 'GET';
+
+	/**
+	 * HEAD method
+	 *
+	 * @var string
+	 */
+	const HEAD = 'HEAD';
+
+	/**
+	 * DELETE method
+	 *
+	 * @var string
+	 */
+	const DELETE = 'DELETE';
+
+	/**
+	 * OPTIONS method
+	 *
+	 * @var string
+	 */
+	const OPTIONS = 'OPTIONS';
+
+	/**
+	 * TRACE method
+	 *
+	 * @var string
+	 */
+	const TRACE = 'TRACE';
+
+	/**
+	 * PATCH method
+	 *
+	 * @link https://tools.ietf.org/html/rfc5789
+	 * @var string
+	 */
+	const PATCH = 'PATCH';
+
+	/**
+	 * Default size of buffer size to read streams
+	 *
+	 * @var integer
+	 */
+	const BUFFER_SIZE = 1160;
+
+	/**
+	 * Current version of Requests
+	 *
+	 * @var string
+	 */
+	const VERSION = '1.8.1';
+
+	/**
+	 * Registered transport classes
+	 *
+	 * @var array
+	 */
+	protected static $transports = array();
+
+	/**
+	 * Selected transport name
+	 *
+	 * Use {@see get_transport()} instead
+	 *
+	 * @var array
+	 */
+	public static $transport = array();
+
+	/**
+	 * Default certificate path.
+	 *
+	 * @see \WpOrg\Requests\Requests::get_certificate_path()
+	 * @see \WpOrg\Requests\Requests::set_certificate_path()
+	 *
+	 * @var string
+	 */
+	protected static $certificate_path;
+
+	/**
+	 * This is a static class, do not instantiate it
+	 *
+	 * @codeCoverageIgnore
+	 */
+	private function __construct() {}
+
+	/**
+	 * Register a transport
+	 *
+	 * @param string $transport Transport class to add, must support the \WpOrg\Requests\Transport interface
+	 */
+	public static function add_transport($transport) {
+		if (empty(self::$transports)) {
+			self::$transports = array(
+				Curl::class,
+				Fsockopen::class,
+			);
+		}
+
+		self::$transports = array_merge(self::$transports, array($transport));
+	}
+
+	/**
+	 * Get a working transport
+	 *
+	 * @throws \WpOrg\Requests\Exception If no valid transport is found (`notransport`)
+	 * @return \WpOrg\Requests\Transport
+	 */
+	protected static function get_transport($capabilities = array()) {
+		// Caching code, don't bother testing coverage
+		// @codeCoverageIgnoreStart
+		// array of capabilities as a string to be used as an array key
+		ksort($capabilities);
+		$cap_string = serialize($capabilities);
+
+		// Don't search for a transport if it's already been done for these $capabilities
+		if (isset(self::$transport[$cap_string]) && self::$transport[$cap_string] !== null) {
+			$class = self::$transport[$cap_string];
+			return new $class();
+		}
+		// @codeCoverageIgnoreEnd
+
+		if (empty(self::$transports)) {
+			self::$transports = array(
+				Curl::class,
+				Fsockopen::class,
+			);
+		}
+
+		// Find us a working transport
+		foreach (self::$transports as $class) {
+			if (!class_exists($class)) {
+				continue;
+			}
+
+			$result = call_user_func(array($class, 'test'), $capabilities);
+			if ($result) {
+				self::$transport[$cap_string] = $class;
+				break;
+			}
+		}
+		if (self::$transport[$cap_string] === null) {
+			throw new Exception('No working transports found', 'notransport', self::$transports);
+		}
+
+		$class = self::$transport[$cap_string];
+		return new $class();
+	}
+
+	/**#@+
+	 * @see request()
+	 * @param string $url
+	 * @param array $headers
+	 * @param array $options
+	 * @return \WpOrg\Requests\Response
+	 */
+	/**
+	 * Send a GET request
+	 */
+	public static function get($url, $headers = array(), $options = array()) {
+		return self::request($url, $headers, null, self::GET, $options);
+	}
+
+	/**
+	 * Send a HEAD request
+	 */
+	public static function head($url, $headers = array(), $options = array()) {
+		return self::request($url, $headers, null, self::HEAD, $options);
+	}
+
+	/**
+	 * Send a DELETE request
+	 */
+	public static function delete($url, $headers = array(), $options = array()) {
+		return self::request($url, $headers, null, self::DELETE, $options);
+	}
+
+	/**
+	 * Send a TRACE request
+	 */
+	public static function trace($url, $headers = array(), $options = array()) {
+		return self::request($url, $headers, null, self::TRACE, $options);
+	}
+	/**#@-*/
+
+	/**#@+
+	 * @see request()
+	 * @param string $url
+	 * @param array $headers
+	 * @param array $data
+	 * @param array $options
+	 * @return \WpOrg\Requests\Response
+	 */
+	/**
+	 * Send a POST request
+	 */
+	public static function post($url, $headers = array(), $data = array(), $options = array()) {
+		return self::request($url, $headers, $data, self::POST, $options);
+	}
+	/**
+	 * Send a PUT request
+	 */
+	public static function put($url, $headers = array(), $data = array(), $options = array()) {
+		return self::request($url, $headers, $data, self::PUT, $options);
+	}
+
+	/**
+	 * Send an OPTIONS request
+	 */
+	public static function options($url, $headers = array(), $data = array(), $options = array()) {
+		return self::request($url, $headers, $data, self::OPTIONS, $options);
+	}
+
+	/**
+	 * Send a PATCH request
+	 *
+	 * Note: Unlike {@see post} and {@see put}, `$headers` is required, as the
+	 * specification recommends that should send an ETag
+	 *
+	 * @link https://tools.ietf.org/html/rfc5789
+	 */
+	public static function patch($url, $headers, $data = array(), $options = array()) {
+		return self::request($url, $headers, $data, self::PATCH, $options);
+	}
+	/**#@-*/
+
+	/**
+	 * Main interface for HTTP requests
+	 *
+	 * This method initiates a request and sends it via a transport before
+	 * parsing.
+	 *
+	 * The `$options` parameter takes an associative array with the following
+	 * options:
+	 *
+	 * - `timeout`: How long should we wait for a response?
+	 *    Note: for cURL, a minimum of 1 second applies, as DNS resolution
+	 *    operates at second-resolution only.
+	 *    (float, seconds with a millisecond precision, default: 10, example: 0.01)
+	 * - `connect_timeout`: How long should we wait while trying to connect?
+	 *    (float, seconds with a millisecond precision, default: 10, example: 0.01)
+	 * - `useragent`: Useragent to send to the server
+	 *    (string, default: php-requests/$version)
+	 * - `follow_redirects`: Should we follow 3xx redirects?
+	 *    (boolean, default: true)
+	 * - `redirects`: How many times should we redirect before erroring?
+	 *    (integer, default: 10)
+	 * - `blocking`: Should we block processing on this request?
+	 *    (boolean, default: true)
+	 * - `filename`: File to stream the body to instead.
+	 *    (string|boolean, default: false)
+	 * - `auth`: Authentication handler or array of user/password details to use
+	 *    for Basic authentication
+	 *    (\WpOrg\Requests\Auth|array|boolean, default: false)
+	 * - `proxy`: Proxy details to use for proxy by-passing and authentication
+	 *    (\WpOrg\Requests\Proxy|array|string|boolean, default: false)
+	 * - `max_bytes`: Limit for the response body size.
+	 *    (integer|boolean, default: false)
+	 * - `idn`: Enable IDN parsing
+	 *    (boolean, default: true)
+	 * - `transport`: Custom transport. Either a class name, or a
+	 *    transport object. Defaults to the first working transport from
+	 *    {@see getTransport()}
+	 *    (string|\WpOrg\Requests\Transport, default: {@see getTransport()})
+	 * - `hooks`: Hooks handler.
+	 *    (\WpOrg\Requests\Hooker, default: new WpOrg\Requests\Hooks())
+	 * - `verify`: Should we verify SSL certificates? Allows passing in a custom
+	 *    certificate file as a string. (Using true uses the system-wide root
+	 *    certificate store instead, but this may have different behaviour
+	 *    across transports.)
+	 *    (string|boolean, default: src/Transport/cacert.pem)
+	 * - `verifyname`: Should we verify the common name in the SSL certificate?
+	 *    (boolean, default: true)
+	 * - `data_format`: How should we send the `$data` parameter?
+	 *    (string, one of 'query' or 'body', default: 'query' for
+	 *    HEAD/GET/DELETE, 'body' for POST/PUT/OPTIONS/PATCH)
+	 *
+	 * @throws \WpOrg\Requests\Exception On invalid URLs (`nonhttp`)
+	 *
+	 * @param string $url URL to request
+	 * @param array $headers Extra headers to send with the request
+	 * @param array|null $data Data to send either as a query string for GET/HEAD requests, or in the body for POST requests
+	 * @param string $type HTTP request type (use Requests constants)
+	 * @param array $options Options for the request (see description for more information)
+	 * @return \WpOrg\Requests\Response
+	 */
+	public static function request($url, $headers = array(), $data = array(), $type = self::GET, $options = array()) {
+		if (empty($options['type'])) {
+			$options['type'] = $type;
+		}
+		$options = array_merge(self::get_default_options(), $options);
+
+		self::set_defaults($url, $headers, $data, $type, $options);
+
+		$options['hooks']->dispatch('requests.before_request', array(&$url, &$headers, &$data, &$type, &$options));
+
+		if (!empty($options['transport'])) {
+			$transport = $options['transport'];
+
+			if (is_string($options['transport'])) {
+				$transport = new $transport();
+			}
+		}
+		else {
+			$need_ssl     = (stripos($url, 'https://') === 0);
+			$capabilities = array('ssl' => $need_ssl);
+			$transport    = self::get_transport($capabilities);
+		}
+		$response = $transport->request($url, $headers, $data, $options);
+
+		$options['hooks']->dispatch('requests.before_parse', array(&$response, $url, $headers, $data, $type, $options));
+
+		return self::parse_response($response, $url, $headers, $data, $options);
+	}
+
+	/**
+	 * Send multiple HTTP requests simultaneously
+	 *
+	 * The `$requests` parameter takes an associative or indexed array of
+	 * request fields. The key of each request can be used to match up the
+	 * request with the returned data, or with the request passed into your
+	 * `multiple.request.complete` callback.
+	 *
+	 * The request fields value is an associative array with the following keys:
+	 *
+	 * - `url`: Request URL Same as the `$url` parameter to
+	 *    {@see \WpOrg\Requests\Requests::request}
+	 *    (string, required)
+	 * - `headers`: Associative array of header fields. Same as the `$headers`
+	 *    parameter to {@see \WpOrg\Requests\Requests::request}
+	 *    (array, default: `array()`)
+	 * - `data`: Associative array of data fields or a string. Same as the
+	 *    `$data` parameter to {@see \WpOrg\Requests\Requests::request}
+	 *    (array|string, default: `array()`)
+	 * - `type`: HTTP request type (use \WpOrg\Requests\Requests constants). Same as the `$type`
+	 *    parameter to {@see \WpOrg\Requests\Requests::request}
+	 *    (string, default: `\WpOrg\Requests\Requests::GET`)
+	 * - `cookies`: Associative array of cookie name to value, or cookie jar.
+	 *    (array|\WpOrg\Requests\Cookie\Jar)
+	 *
+	 * If the `$options` parameter is specified, individual requests will
+	 * inherit options from it. This can be used to use a single hooking system,
+	 * or set all the types to `\WpOrg\Requests\Requests::POST`, for example.
+	 *
+	 * In addition, the `$options` parameter takes the following global options:
+	 *
+	 * - `complete`: A callback for when a request is complete. Takes two
+	 *    parameters, a \WpOrg\Requests\Response/\WpOrg\Requests\Exception reference, and the
+	 *    ID from the request array (Note: this can also be overridden on a
+	 *    per-request basis, although that's a little silly)
+	 *    (callback)
+	 *
+	 * @param array $requests Requests data (see description for more information)
+	 * @param array $options Global and default options (see {@see \WpOrg\Requests\Requests::request})
+	 * @return array Responses (either \WpOrg\Requests\Response or a \WpOrg\Requests\Exception object)
+	 */
+	public static function request_multiple($requests, $options = array()) {
+		$options = array_merge(self::get_default_options(true), $options);
+
+		if (!empty($options['hooks'])) {
+			$options['hooks']->register('transport.internal.parse_response', array(static::class, 'parse_multiple'));
+			if (!empty($options['complete'])) {
+				$options['hooks']->register('multiple.request.complete', $options['complete']);
+			}
+		}
+
+		foreach ($requests as $id => &$request) {
+			if (!isset($request['headers'])) {
+				$request['headers'] = array();
+			}
+			if (!isset($request['data'])) {
+				$request['data'] = array();
+			}
+			if (!isset($request['type'])) {
+				$request['type'] = self::GET;
+			}
+			if (!isset($request['options'])) {
+				$request['options']         = $options;
+				$request['options']['type'] = $request['type'];
+			}
+			else {
+				if (empty($request['options']['type'])) {
+					$request['options']['type'] = $request['type'];
+				}
+				$request['options'] = array_merge($options, $request['options']);
+			}
+
+			self::set_defaults($request['url'], $request['headers'], $request['data'], $request['type'], $request['options']);
+
+			// Ensure we only hook in once
+			if ($request['options']['hooks'] !== $options['hooks']) {
+				$request['options']['hooks']->register('transport.internal.parse_response', array(static::class, 'parse_multiple'));
+				if (!empty($request['options']['complete'])) {
+					$request['options']['hooks']->register('multiple.request.complete', $request['options']['complete']);
+				}
+			}
+		}
+		unset($request);
+
+		if (!empty($options['transport'])) {
+			$transport = $options['transport'];
+
+			if (is_string($options['transport'])) {
+				$transport = new $transport();
+			}
+		}
+		else {
+			$transport = self::get_transport();
+		}
+		$responses = $transport->request_multiple($requests, $options);
+
+		foreach ($responses as $id => &$response) {
+			// If our hook got messed with somehow, ensure we end up with the
+			// correct response
+			if (is_string($response)) {
+				$request = $requests[$id];
+				self::parse_multiple($response, $request);
+				$request['options']['hooks']->dispatch('multiple.request.complete', array(&$response, $id));
+			}
+		}
+
+		return $responses;
+	}
+
+	/**
+	 * Get the default options
+	 *
+	 * @see \WpOrg\Requests\Requests::request() for values returned by this method
+	 * @param boolean $multirequest Is this a multirequest?
+	 * @return array Default option values
+	 */
+	protected static function get_default_options($multirequest = false) {
+		$defaults = array(
+			'timeout'          => 10,
+			'connect_timeout'  => 10,
+			'useragent'        => 'php-requests/' . self::VERSION,
+			'protocol_version' => 1.1,
+			'redirected'       => 0,
+			'redirects'        => 10,
+			'follow_redirects' => true,
+			'blocking'         => true,
+			'type'             => self::GET,
+			'filename'         => false,
+			'auth'             => false,
+			'proxy'            => false,
+			'cookies'          => false,
+			'max_bytes'        => false,
+			'idn'              => true,
+			'hooks'            => null,
+			'transport'        => null,
+			'verify'           => self::get_certificate_path(),
+			'verifyname'       => true,
+		);
+		if ($multirequest !== false) {
+			$defaults['complete'] = null;
+		}
+		return $defaults;
+	}
+
+	/**
+	 * Get default certificate path.
+	 *
+	 * @return string Default certificate path.
+	 */
+	public static function get_certificate_path() {
+		if (!empty(self::$certificate_path)) {
+			return self::$certificate_path;
+		}
+
+		return __DIR__ . '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/Transport/cacert.pem';
+	}
+
+	/**
+	 * Set default certificate path.
+	 *
+	 * @param string $path Certificate path, pointing to a PEM file.
+	 */
+	public static function set_certificate_path($path) {
+		self::$certificate_path = $path;
+	}
+
+	/**
+	 * Set the default values
+	 *
+	 * @param string $url URL to request
+	 * @param array $headers Extra headers to send with the request
+	 * @param array|null $data Data to send either as a query string for GET/HEAD requests, or in the body for POST requests
+	 * @param string $type HTTP request type
+	 * @param array $options Options for the request
+	 * @return array $options
+	 */
+	protected static function set_defaults(&$url, &$headers, &$data, &$type, &$options) {
+		if (!preg_match('/^http(s)?:\/\//i', $url, $matches)) {
+			throw new Exception('Only HTTP(S) requests are handled.', 'nonhttp', $url);
+		}
+
+		if (empty($options['hooks'])) {
+			$options['hooks'] = new Hooks();
+		}
+
+		if (is_array($options['auth'])) {
+			$options['auth'] = new Basic($options['auth']);
+		}
+		if ($options['auth'] !== false) {
+			$options['auth']->register($options['hooks']);
+		}
+
+		if (is_string($options['proxy']) || is_array($options['proxy'])) {
+			$options['proxy'] = new Http($options['proxy']);
+		}
+		if ($options['proxy'] !== false) {
+			$options['proxy']->register($options['hooks']);
+		}
+
+		if (is_array($options['cookies'])) {
+			$options['cookies'] = new Jar($options['cookies']);
+		}
+		elseif (empty($options['cookies'])) {
+			$options['cookies'] = new Jar();
+		}
+		if ($options['cookies'] !== false) {
+			$options['cookies']->register($options['hooks']);
+		}
+
+		if ($options['idn'] !== false) {
+			$iri       = new Iri($url);
+			$iri->host = IdnaEncoder::encode($iri->ihost);
+			$url       = $iri->uri;
+		}
+
+		// Massage the type to ensure we support it.
+		$type = strtoupper($type);
+
+		if (!isset($options['data_format'])) {
+			if (in_array($type, array(self::HEAD, self::GET, self::DELETE), true)) {
+				$options['data_format'] = 'query';
+			}
+			else {
+				$options['data_format'] = 'body';
+			}
+		}
+	}
+
+	/**
+	 * HTTP response parser
+	 *
+	 * @throws \WpOrg\Requests\Exception On missing head/body separator (`requests.no_crlf_separator`)
+	 * @throws \WpOrg\Requests\Exception On missing head/body separator (`noversion`)
+	 * @throws \WpOrg\Requests\Exception On missing head/body separator (`toomanyredirects`)
+	 *
+	 * @param string $headers Full response text including headers and body
+	 * @param string $url Original request URL
+	 * @param array $req_headers Original $headers array passed to {@link request()}, in case we need to follow redirects
+	 * @param array $req_data Original $data array passed to {@link request()}, in case we need to follow redirects
+	 * @param array $options Original $options array passed to {@link request()}, in case we need to follow redirects
+	 * @return \WpOrg\Requests\Response
+	 */
+	protected static function parse_response($headers, $url, $req_headers, $req_data, $options) {
+		$return = new Response();
+		if (!$options['blocking']) {
+			return $return;
+		}
+
+		$return->raw  = $headers;
+		$return->url  = (string) $url;
+		$return->body = '';
+
+		if (!$options['filename']) {
+			$pos = strpos($headers, "\r\n\r\n");
+			if ($pos === false) {
+				// Crap!
+				throw new Exception('Missing header/body separator', 'requests.no_crlf_separator');
+			}
+
+			$headers = substr($return->raw, 0, $pos);
+			// Headers will always be separated from the body by two new lines - `\n\r\n\r`.
+			$body = substr($return->raw, $pos + 4);
+			if (!empty($body)) {
+				$return->body = $body;
+			}
+		}
+		// Pretend CRLF = LF for compatibility (RFC 2616, section 19.3)
+		$headers = str_replace("\r\n", "\n", $headers);
+		// Unfold headers (replace [CRLF] 1*( SP | HT ) with SP) as per RFC 2616 (section 2.2)
+		$headers = preg_replace('/\n[ \t]/', ' ', $headers);
+		$headers = explode("\n", $headers);
+		preg_match('#^HTTP/(1\.\d)[ \t]+(\d+)#i', array_shift($headers), $matches);
+		if (empty($matches)) {
+			throw new Exception('Response could not be parsed', 'noversion', $headers);
+		}
+		$return->protocol_version = (float) $matches[1];
+		$return->status_code      = (int) $matches[2];
+		if ($return->status_code >= 200 && $return->status_code < 300) {
+			$return->success = true;
+		}
+
+		foreach ($headers as $header) {
+			list($key, $value) = explode(':', $header, 2);
+			$value             = trim($value);
+			preg_replace('#(\s+)#i', ' ', $value);
+			$return->headers[$key] = $value;
+		}
+		if (isset($return->headers['transfer-encoding'])) {
+			$return->body = self::decode_chunked($return->body);
+			unset($return->headers['transfer-encoding']);
+		}
+		if (isset($return->headers['content-encoding'])) {
+			$return->body = self::decompress($return->body);
+		}
+
+		//fsockopen and cURL compatibility
+		if (isset($return->headers['connection'])) {
+			unset($return->headers['connection']);
+		}
+
+		$options['hooks']->dispatch('requests.before_redirect_check', array(&$return, $req_headers, $req_data, $options));
+
+		if ($return->is_redirect() && $options['follow_redirects'] === true) {
+			if (isset($return->headers['location']) && $options['redirected'] < $options['redirects']) {
+				if ($return->status_code === 303) {
+					$options['type'] = self::GET;
+				}
+				$options['redirected']++;
+				$location = $return->headers['location'];
+				if (strpos($location, 'http://') !== 0 && strpos($location, 'https://') !== 0) {
+					// relative redirect, for compatibility make it absolute
+					$location = Iri::absolutize($url, $location);
+					$location = $location->uri;
+				}
+
+				$hook_args = array(
+					&$location,
+					&$req_headers,
+					&$req_data,
+					&$options,
+					$return,
+				);
+				$options['hooks']->dispatch('requests.before_redirect', $hook_args);
+				$redirected            = self::request($location, $req_headers, $req_data, $options['type'], $options);
+				$redirected->history[] = $return;
+				return $redirected;
+			}
+			elseif ($options['redirected'] >= $options['redirects']) {
+				throw new Exception('Too many redirects', 'toomanyredirects', $return);
+			}
+		}
+
+		$return->redirects = $options['redirected'];
+
+		$options['hooks']->dispatch('requests.after_request', array(&$return, $req_headers, $req_data, $options));
+		return $return;
+	}
+
+	/**
+	 * Callback for `transport.internal.parse_response`
+	 *
+	 * Internal use only. Converts a raw HTTP response to a \WpOrg\Requests\Response
+	 * while still executing a multiple request.
+	 *
+	 * @param string $response Full response text including headers and body (will be overwritten with Response instance)
+	 * @param array $request Request data as passed into {@see \WpOrg\Requests\Requests::request_multiple()}
+	 * @return null `$response` is either set to a \WpOrg\Requests\Response instance, or a \WpOrg\Requests\Exception object
+	 */
+	public static function parse_multiple(&$response, $request) {
+		try {
+			$url      = $request['url'];
+			$headers  = $request['headers'];
+			$data     = $request['data'];
+			$options  = $request['options'];
+			$response = self::parse_response($response, $url, $headers, $data, $options);
+		}
+		catch (Exception $e) {
+			$response = $e;
+		}
+	}
+
+	/**
+	 * Decoded a chunked body as per RFC 2616
+	 *
+	 * @see https://tools.ietf.org/html/rfc2616#section-3.6.1
+	 * @param string $data Chunked body
+	 * @return string Decoded body
+	 */
+	protected static function decode_chunked($data) {
+		if (!preg_match('/^([0-9a-f]+)(?:;(?:[\w-]*)(?:=(?:(?:[\w-]*)*|"(?:[^\r\n])*"))?)*\r\n/i', trim($data))) {
+			return $data;
+		}
+
+		$decoded = '';
+		$encoded = $data;
+
+		while (true) {
+			$is_chunked = (bool) preg_match('/^([0-9a-f]+)(?:;(?:[\w-]*)(?:=(?:(?:[\w-]*)*|"(?:[^\r\n])*"))?)*\r\n/i', $encoded, $matches);
+			if (!$is_chunked) {
+				// Looks like it's not chunked after all
+				return $data;
+			}
+
+			$length = hexdec(trim($matches[1]));
+			if ($length === 0) {
+				// Ignore trailer headers
+				return $decoded;
+			}
+
+			$chunk_length = strlen($matches[0]);
+			$decoded     .= substr($encoded, $chunk_length, $length);
+			$encoded      = substr($encoded, $chunk_length + $length + 2);
+
+			if (trim($encoded) === '0' || empty($encoded)) {
+				return $decoded;
+			}
+		}
+
+		// We'll never actually get down here
+		// @codeCoverageIgnoreStart
+	}
+	// @codeCoverageIgnoreEnd
+
+	/**
+	 * Convert a key => value array to a 'key: value' array for headers
+	 *
+	 * @param array $array Dictionary of header values
+	 * @return array List of headers
+	 */
+	public static function flatten($array) {
+		$return = array();
+		foreach ($array as $key => $value) {
+			$return[] = sprintf('%s: %s', $key, $value);
+		}
+		return $return;
+	}
+
+	/**
+	 * Decompress an encoded body
+	 *
+	 * Implements gzip, compress and deflate. Guesses which it is by attempting
+	 * to decode.
+	 *
+	 * @param string $data Compressed data in one of the above formats
+	 * @return string Decompressed string
+	 */
+	public static function decompress($data) {
+		if (substr($data, 0, 2) !== "\x1f\x8b" && substr($data, 0, 2) !== "\x78\x9c") {
+			// Not actually compressed. Probably cURL ruining this for us.
+			return $data;
+		}
+
+		if (function_exists('gzdecode')) {
+			$decoded = @gzdecode($data);
+			if ($decoded !== false) {
+				return $decoded;
+			}
+		}
+
+		if (function_exists('gzinflate')) {
+			$decoded = @gzinflate($data);
+			if ($decoded !== false) {
+				return $decoded;
+			}
+		}
+
+		$decoded = self::compatible_gzinflate($data);
+		if ($decoded !== false) {
+			return $decoded;
+		}
+
+		if (function_exists('gzuncompress')) {
+			$decoded = @gzuncompress($data);
+			if ($decoded !== false) {
+				return $decoded;
+			}
+		}
+
+		return $data;
+	}
+
+	/**
+	 * Decompression of deflated string while staying compatible with the majority of servers.
+	 *
+	 * Certain Servers will return deflated data with headers which PHP's gzinflate()
+	 * function cannot handle out of the box. The following function has been created from
+	 * various snippets on the gzinflate() PHP documentation.
+	 *
+	 * Warning: Magic numbers within. Due to the potential different formats that the compressed
+	 * data may be returned in, some "magic offsets" are needed to ensure proper decompression
+	 * takes place. For a simple progmatic way to determine the magic offset in use, see:
+	 * https://core.trac.wordpress.org/ticket/18273
+	 *
+	 * @since 2.8.1
+	 * @link https://core.trac.wordpress.org/ticket/18273
+	 * @link https://www.php.net/gzinflate#70875
+	 * @link https://www.php.net/gzinflate#77336
+	 *
+	 * @param string $gz_data String to decompress.
+	 * @return string|bool False on failure.
+	 */
+	public static function compatible_gzinflate($gz_data) {
+		// Compressed data might contain a full zlib header, if so strip it for
+		// gzinflate()
+		if (substr($gz_data, 0, 3) === "\x1f\x8b\x08") {
+			$i   = 10;
+			$flg = ord(substr($gz_data, 3, 1));
+			if ($flg > 0) {
+				if ($flg & 4) {
+					list($xlen) = unpack('v', substr($gz_data, $i, 2));
+					$i         += 2 + $xlen;
+				}
+				if ($flg & 8) {
+					$i = strpos($gz_data, "\0", $i) + 1;
+				}
+				if ($flg & 16) {
+					$i = strpos($gz_data, "\0", $i) + 1;
+				}
+				if ($flg & 2) {
+					$i += 2;
+				}
+			}
+			$decompressed = self::compatible_gzinflate(substr($gz_data, $i));
+			if ($decompressed !== false) {
+				return $decompressed;
+			}
+		}
+
+		// If the data is Huffman Encoded, we must first strip the leading 2
+		// byte Huffman marker for gzinflate()
+		// The response is Huffman coded by many compressors such as
+		// java.util.zip.Deflater, Ruby’s Zlib::Deflate, and .NET's
+		// System.IO.Compression.DeflateStream.
+		//
+		// See https://decompres.blogspot.com/ for a quick explanation of this
+		// data type
+		$huffman_encoded = false;
+
+		// low nibble of first byte should be 0x08
+		list(, $first_nibble) = unpack('h', $gz_data);
+
+		// First 2 bytes should be divisible by 0x1F
+		list(, $first_two_bytes) = unpack('n', $gz_data);
+
+		if ($first_nibble === 0x08 && ($first_two_bytes % 0x1F) === 0) {
+			$huffman_encoded = true;
+		}
+
+		if ($huffman_encoded) {
+			$decompressed = @gzinflate(substr($gz_data, 2));
+			if ($decompressed !== false) {
+				return $decompressed;
+			}
+		}
+
+		if (substr($gz_data, 0, 4) === "\x50\x4b\x03\x04") {
+			// ZIP file format header
+			// Offset 6: 2 bytes, General-purpose field
+			// Offset 26: 2 bytes, filename length
+			// Offset 28: 2 bytes, optional field length
+			// Offset 30: Filename field, followed by optional field, followed
+			// immediately by data
+			list(, $general_purpose_flag) = unpack('v', substr($gz_data, 6, 2));
+
+			// If the file has been compressed on the fly, 0x08 bit is set of
+			// the general purpose field. We can use this to differentiate
+			// between a compressed document, and a ZIP file
+			$zip_compressed_on_the_fly = ((0x08 & $general_purpose_flag) === 0x08);
+
+			if (!$zip_compressed_on_the_fly) {
+				// Don't attempt to decode a compressed zip file
+				return $gz_data;
+			}
+
+			// Determine the first byte of data, based on the above ZIP header
+			// offsets:
+			$first_file_start = array_sum(unpack('v2', substr($gz_data, 26, 4)));
+			$decompressed     = @gzinflate(substr($gz_data, 30 + $first_file_start));
+			if ($decompressed !== false) {
+				return $decompressed;
+			}
+			return false;
+		}
+
+		// Finally fall back to straight gzinflate
+		$decompressed = @gzinflate($gz_data);
+		if ($decompressed !== false) {
+			return $decompressed;
+		}
+
+		// Fallback for all above failing, not expected, but included for
+		// debugging and preventing regressions and to track stats
+		$decompressed = @gzinflate(substr($gz_data, 2));
+		if ($decompressed !== false) {
+			return $decompressed;
+		}
+
+		return false;
+	}
+
+	public static function match_domain($host, $reference) {
+		// Check for a direct match
+		if ($host === $reference) {
+			return true;
+		}
+
+		// Calculate the valid wildcard match if the host is not an IP address
+		// Also validates that the host has 3 parts or more, as per Firefox's
+		// ruleset.
+		$parts = explode('.', $host);
+		if (ip2long($host) === false && count($parts) >= 3) {
+			$parts[0] = '*';
+			$wildcard = implode('.', $parts);
+			if ($wildcard === $reference) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+}
diff --git a/library/Requests/Response.php b/src/Response.php
similarity index 62%
rename from library/Requests/Response.php
rename to src/Response.php
index 20861dfb8..b895c2bf7 100644
--- a/library/Requests/Response.php
+++ b/src/Response.php
@@ -2,23 +2,30 @@
 /**
  * HTTP response class
  *
- * Contains a response from Requests::request()
+ * Contains a response from \WpOrg\Requests\Requests::request()
  * @package Requests
  */
 
+namespace WpOrg\Requests;
+
+use WpOrg\Requests\Cookie\Jar;
+use WpOrg\Requests\Exception;
+use WpOrg\Requests\Exception\Http;
+use WpOrg\Requests\Response\Headers;
+
 /**
  * HTTP response class
  *
- * Contains a response from Requests::request()
+ * Contains a response from \WpOrg\Requests\Requests::request()
  * @package Requests
  */
-class Requests_Response {
+class Response {
 	/**
 	 * Constructor
 	 */
 	public function __construct() {
-		$this->headers = new Requests_Response_Headers();
-		$this->cookies = new Requests_Cookie_Jar();
+		$this->headers = new Headers();
+		$this->cookies = new Jar();
 	}
 
 	/**
@@ -38,7 +45,7 @@ public function __construct() {
 	/**
 	 * Headers, as an associative array
 	 *
-	 * @var Requests_Response_Headers Array-like object representing headers
+	 * @var \WpOrg\Requests\Response\Headers Array-like object representing headers
 	 */
 	public $headers = array();
 
@@ -80,14 +87,14 @@ public function __construct() {
 	/**
 	 * Previous requests (from redirects)
 	 *
-	 * @var array Array of Requests_Response objects
+	 * @var array Array of \WpOrg\Requests\Response objects
 	 */
 	public $history = array();
 
 	/**
 	 * Cookies from the request
 	 *
-	 * @var Requests_Cookie_Jar Array-like object representing a cookie jar
+	 * @var \WpOrg\Requests\Cookie\Jar Array-like object representing a cookie jar
 	 */
 	public $cookies = array();
 
@@ -104,18 +111,18 @@ public function is_redirect() {
 	/**
 	 * Throws an exception if the request was not successful
 	 *
-	 * @throws Requests_Exception If `$allow_redirects` is false, and code is 3xx (`response.no_redirects`)
-	 * @throws Requests_Exception_HTTP On non-successful status code. Exception class corresponds to code (e.g. {@see Requests_Exception_HTTP_404})
+	 * @throws \WpOrg\Requests\Exception If `$allow_redirects` is false, and code is 3xx (`response.no_redirects`)
+	 * @throws \WpOrg\Requests\Exception\Http On non-successful status code. Exception class corresponds to "Status" + code (e.g. {@see \WpOrg\Requests\Exception\Http\Status404})
 	 * @param boolean $allow_redirects Set to false to throw on a 3xx as well
 	 */
 	public function throw_for_status($allow_redirects = true) {
 		if ($this->is_redirect()) {
 			if (!$allow_redirects) {
-				throw new Requests_Exception('Redirection not allowed', 'response.no_redirects', $this);
+				throw new Exception('Redirection not allowed', 'response.no_redirects', $this);
 			}
 		}
 		elseif (!$this->success) {
-			$exception = Requests_Exception_HTTP::get_class($this->status_code);
+			$exception = Http::get_class($this->status_code);
 			throw new $exception(null, $this);
 		}
 	}
diff --git a/library/Requests/Response/Headers.php b/src/Response/Headers.php
similarity index 78%
rename from library/Requests/Response/Headers.php
rename to src/Response/Headers.php
index 12db128ae..682eb6c39 100644
--- a/library/Requests/Response/Headers.php
+++ b/src/Response/Headers.php
@@ -5,12 +5,18 @@
  * @package Requests
  */
 
+namespace WpOrg\Requests\Response;
+
+use WpOrg\Requests\Exception;
+use WpOrg\Requests\Utility\CaseInsensitiveDictionary;
+use WpOrg\Requests\Utility\FilteredIterator;
+
 /**
  * Case-insensitive dictionary, suitable for HTTP headers
  *
  * @package Requests
  */
-class Requests_Response_Headers extends Requests_Utility_CaseInsensitiveDictionary {
+class Headers extends CaseInsensitiveDictionary {
 	/**
 	 * Get the given header
 	 *
@@ -35,14 +41,14 @@ public function offsetGet($key) {
 	/**
 	 * Set the given item
 	 *
-	 * @throws Requests_Exception On attempting to use dictionary as list (`invalidset`)
+	 * @throws \WpOrg\Requests\Exception On attempting to use dictionary as list (`invalidset`)
 	 *
 	 * @param string $key Item name
 	 * @param string $value Item value
 	 */
 	public function offsetSet($key, $value) {
 		if ($key === null) {
-			throw new Requests_Exception('Object is a dictionary, not a list', 'invalidset');
+			throw new Exception('Object is a dictionary, not a list', 'invalidset');
 		}
 
 		$key = strtolower($key);
@@ -90,9 +96,9 @@ public function flatten($value) {
 	 * Get an iterator for the data
 	 *
 	 * Converts the internal
-	 * @return ArrayIterator
+	 * @return \ArrayIterator
 	 */
 	public function getIterator() {
-		return new Requests_Utility_FilteredIterator($this->data, array($this, 'flatten'));
+		return new FilteredIterator($this->data, array($this, 'flatten'));
 	}
 }
diff --git a/library/Requests/Session.php b/src/Session.php
similarity index 87%
rename from library/Requests/Session.php
rename to src/Session.php
index b2e10991d..1e5753199 100644
--- a/library/Requests/Session.php
+++ b/src/Session.php
@@ -6,6 +6,12 @@
  * @subpackage Session Handler
  */
 
+namespace WpOrg\Requests;
+
+use WpOrg\Requests\Cookie\Jar;
+use WpOrg\Requests\Iri;
+use WpOrg\Requests\Requests;
+
 /**
  * Session handler for persistent requests and default parameters
  *
@@ -17,7 +23,7 @@
  * @package Requests
  * @subpackage Session Handler
  */
-class Requests_Session {
+class Session {
 	/**
 	 * Base URL for requests
 	 *
@@ -72,7 +78,7 @@ public function __construct($url = null, $headers = array(), $data = array(), $o
 		$this->options = $options;
 
 		if (empty($this->options['cookies'])) {
-			$this->options['cookies'] = new Requests_Cookie_Jar();
+			$this->options['cookies'] = new Jar();
 		}
 	}
 
@@ -125,7 +131,7 @@ public function __unset($key) {
 	 * @param string $url
 	 * @param array $headers
 	 * @param array $options
-	 * @return Requests_Response
+	 * @return \WpOrg\Requests\Response
 	 */
 	/**
 	 * Send a GET request
@@ -155,7 +161,7 @@ public function delete($url, $headers = array(), $options = array()) {
 	 * @param array $headers
 	 * @param array $data
 	 * @param array $options
-	 * @return Requests_Response
+	 * @return \WpOrg\Requests\Response
 	 */
 	/**
 	 * Send a POST request
@@ -190,16 +196,16 @@ public function patch($url, $headers, $data = array(), $options = array()) {
 	 * This method initiates a request and sends it via a transport before
 	 * parsing.
 	 *
-	 * @see Requests::request()
+	 * @see \WpOrg\Requests\Requests::request()
 	 *
-	 * @throws Requests_Exception On invalid URLs (`nonhttp`)
+	 * @throws \WpOrg\Requests\Exception On invalid URLs (`nonhttp`)
 	 *
 	 * @param string $url URL to request
 	 * @param array $headers Extra headers to send with the request
 	 * @param array|null $data Data to send either as a query string for GET/HEAD requests, or in the body for POST requests
-	 * @param string $type HTTP request type (use Requests constants)
-	 * @param array $options Options for the request (see {@see Requests::request})
-	 * @return Requests_Response
+	 * @param string $type HTTP request type (use \WpOrg\Requests\Requests constants)
+	 * @param array $options Options for the request (see {@see \WpOrg\Requests\Requests::request})
+	 * @return \WpOrg\Requests\Response
 	 */
 	public function request($url, $headers = array(), $data = array(), $type = Requests::GET, $options = array()) {
 		$request = $this->merge_request(compact('url', 'headers', 'data', 'options'));
@@ -210,11 +216,11 @@ public function request($url, $headers = array(), $data = array(), $type = Reque
 	/**
 	 * Send multiple HTTP requests simultaneously
 	 *
-	 * @see Requests::request_multiple()
+	 * @see \WpOrg\Requests\Requests::request_multiple()
 	 *
-	 * @param array $requests Requests data (see {@see Requests::request_multiple})
-	 * @param array $options Global and default options (see {@see Requests::request})
-	 * @return array Responses (either Requests_Response or a Requests_Exception object)
+	 * @param array $requests Requests data (see {@see \WpOrg\Requests\Requests::request_multiple})
+	 * @param array $options Global and default options (see {@see \WpOrg\Requests\Requests::request})
+	 * @return array Responses (either \WpOrg\Requests\Response or a \WpOrg\Requests\Exception object)
 	 */
 	public function request_multiple($requests, $options = array()) {
 		foreach ($requests as $key => $request) {
@@ -238,7 +244,7 @@ public function request_multiple($requests, $options = array()) {
 	 */
 	protected function merge_request($request, $merge_options = true) {
 		if ($this->url !== null) {
-			$request['url'] = Requests_IRI::absolutize($this->url, $request['url']);
+			$request['url'] = Iri::absolutize($this->url, $request['url']);
 			$request['url'] = $request['url']->uri;
 		}
 
diff --git a/library/Requests/SSL.php b/src/Ssl.php
similarity index 96%
rename from library/Requests/SSL.php
rename to src/Ssl.php
index f7ecf3fbd..1ac84fdf8 100644
--- a/library/Requests/SSL.php
+++ b/src/Ssl.php
@@ -6,6 +6,8 @@
  * @subpackage Utilities
  */
 
+namespace WpOrg\Requests;
+
 /**
  * SSL utilities for Requests
  *
@@ -14,7 +16,7 @@
  * @package Requests
  * @subpackage Utilities
  */
-class Requests_SSL {
+class Ssl {
 	/**
 	 * Verify the certificate against common name and subject alternative names
 	 *
@@ -23,7 +25,7 @@ class Requests_SSL {
 	 *
 	 * @see https://tools.ietf.org/html/rfc2818#section-3.1 RFC2818, Section 3.1
 	 *
-	 * @throws Requests_Exception On not obtaining a match for the host (`fsockopen.ssl.no_match`)
+	 * @throws \WpOrg\Requests\Exception On not obtaining a match for the host (`fsockopen.ssl.no_match`)
 	 * @param string $host Host name to verify against
 	 * @param array $cert Certificate data from openssl_x509_parse()
 	 * @return bool
diff --git a/library/Requests/Transport.php b/src/Transport.php
similarity index 64%
rename from library/Requests/Transport.php
rename to src/Transport.php
index 5146c01d8..313d7c83a 100644
--- a/library/Requests/Transport.php
+++ b/src/Transport.php
@@ -6,20 +6,22 @@
  * @subpackage Transport
  */
 
+namespace WpOrg\Requests;
+
 /**
  * Base HTTP transport
  *
  * @package Requests
  * @subpackage Transport
  */
-interface Requests_Transport {
+interface Transport {
 	/**
 	 * Perform a request
 	 *
 	 * @param string $url URL to request
 	 * @param array $headers Associative array of request headers
 	 * @param string|array $data Data to send either as the POST body, or as parameters in the URL for a GET/HEAD
-	 * @param array $options Request options, see {@see Requests::response()} for documentation
+	 * @param array $options Request options, see {@see \WpOrg\Requests\Requests::response()} for documentation
 	 * @return string Raw HTTP result
 	 */
 	public function request($url, $headers = array(), $data = array(), $options = array());
@@ -27,9 +29,9 @@ public function request($url, $headers = array(), $data = array(), $options = ar
 	/**
 	 * Send multiple requests simultaneously
 	 *
-	 * @param array $requests Request data (array of 'url', 'headers', 'data', 'options') as per {@see Requests_Transport::request}
-	 * @param array $options Global options, see {@see Requests::response()} for documentation
-	 * @return array Array of Requests_Response objects (may contain Requests_Exception or string responses as well)
+	 * @param array $requests Request data (array of 'url', 'headers', 'data', 'options') as per {@see \WpOrg\Requests\Transport::request}
+	 * @param array $options Global options, see {@see \WpOrg\Requests\Requests::response()} for documentation
+	 * @return array Array of \WpOrg\Requests\Response objects (may contain \WpOrg\Requests\Exception or string responses as well)
 	 */
 	public function request_multiple($requests, $options);
 
diff --git a/library/Requests/Transport/cURL.php b/src/Transport/Curl.php
similarity index 93%
rename from library/Requests/Transport/cURL.php
rename to src/Transport/Curl.php
index 757c0cfef..845b2c8fb 100644
--- a/library/Requests/Transport/cURL.php
+++ b/src/Transport/Curl.php
@@ -6,13 +6,23 @@
  * @subpackage Transport
  */
 
+namespace WpOrg\Requests\Transport;
+
+use RecursiveArrayIterator;
+use RecursiveIteratorIterator;
+use WpOrg\Requests\Exception;
+use WpOrg\Requests\Exception\InvalidArgument;
+use WpOrg\Requests\Exception\Transport\Curl as CurlException;
+use WpOrg\Requests\Requests;
+use WpOrg\Requests\Transport;
+
 /**
  * cURL HTTP transport
  *
  * @package Requests
  * @subpackage Transport
  */
-class Requests_Transport_cURL implements Requests_Transport {
+class Curl implements Transport {
 	const CURL_7_10_5 = 0x070A05;
 	const CURL_7_16_2 = 0x071002;
 
@@ -54,7 +64,7 @@ class Requests_Transport_cURL implements Requests_Transport {
 	/**
 	 * Hook dispatcher instance
 	 *
-	 * @var Requests_Hooks
+	 * @var \WpOrg\Requests\Hooks
 	 */
 	protected $hooks;
 
@@ -121,12 +131,12 @@ public function __destruct() {
 	/**
 	 * Perform a request
 	 *
-	 * @throws Requests_Exception On a cURL error (`curlerror`)
+	 * @throws \WpOrg\Requests\Exception On a cURL error (`curlerror`)
 	 *
 	 * @param string $url URL to request
 	 * @param array $headers Associative array of request headers
 	 * @param string|array $data Data to send either as the POST body, or as parameters in the URL for a GET/HEAD
-	 * @param array $options Request options, see {@see Requests::response()} for documentation
+	 * @param array $options Request options, see {@see \WpOrg\Requests\Requests::response()} for documentation
 	 * @return string Raw HTTP result
 	 */
 	public function request($url, $headers = array(), $data = array(), $options = array()) {
@@ -136,7 +146,7 @@ public function request($url, $headers = array(), $data = array(), $options = ar
 			} elseif (is_int($data) || is_float($data)) {
 				$data = (string) $data;
 			} else {
-				throw new Requests_Exception_InvalidArgument(
+				throw new InvalidArgument(
 					sprintf(
 						'%s: Argument #%d (%s) must be of type %s, %s given',
 						__METHOD__,
@@ -160,7 +170,7 @@ public function request($url, $headers = array(), $data = array(), $options = ar
 			$this->stream_handle = @fopen($options['filename'], 'wb');
 			if ($this->stream_handle === false) {
 				$error = error_get_last();
-				throw new Requests_Exception($error['message'], 'fopen');
+				throw new Exception($error['message'], 'fopen');
 			}
 		}
 
@@ -203,7 +213,7 @@ public function request($url, $headers = array(), $data = array(), $options = ar
 		$this->process_response($response, $options);
 
 		// Need to remove the $this reference from the curl handle.
-		// Otherwise Requests_Transport_cURL wont be garbage collected and the curl_close() will never be called.
+		// Otherwise \WpOrg\Requests\Transport\Curl wont be garbage collected and the curl_close() will never be called.
 		curl_setopt($this->handle, CURLOPT_HEADERFUNCTION, null);
 		curl_setopt($this->handle, CURLOPT_WRITEFUNCTION, null);
 
@@ -215,7 +225,7 @@ public function request($url, $headers = array(), $data = array(), $options = ar
 	 *
 	 * @param array $requests Request data
 	 * @param array $options Global options
-	 * @return array Array of Requests_Response objects (may contain Requests_Exception or string responses as well)
+	 * @return array Array of \WpOrg\Requests\Response objects (may contain \WpOrg\Requests\Exception or string responses as well)
 	 */
 	public function request_multiple($requests, $options) {
 		// If you're not requesting, we can't get any responses ¯\_(ツ)_/¯
@@ -265,9 +275,9 @@ public function request_multiple($requests, $options) {
 				if ($done['result'] !== CURLE_OK) {
 					//get error string for handle.
 					$reason          = curl_error($done['handle']);
-					$exception       = new Requests_Exception_Transport_cURL(
+					$exception       = new CurlException(
 						$reason,
-						Requests_Exception_Transport_cURL::EASY,
+						CurlException::EASY,
 						$done['handle'],
 						$done['result']
 					);
@@ -304,7 +314,7 @@ public function request_multiple($requests, $options) {
 	 * @param string $url URL to request
 	 * @param array $headers Associative array of request headers
 	 * @param string|array $data Data to send either as the POST body, or as parameters in the URL for a GET/HEAD
-	 * @param array $options Request options, see {@see Requests::response()} for documentation
+	 * @param array $options Request options, see {@see \WpOrg\Requests\Requests::response()} for documentation
 	 * @return resource Subrequest's cURL handle
 	 */
 	public function &get_subrequest_handle($url, $headers, $data, $options) {
@@ -331,7 +341,7 @@ public function &get_subrequest_handle($url, $headers, $data, $options) {
 	 * @param string $url URL to request
 	 * @param array $headers Associative array of request headers
 	 * @param string|array $data Data to send either as the POST body, or as parameters in the URL for a GET/HEAD
-	 * @param array $options Request options, see {@see Requests::response()} for documentation
+	 * @param array $options Request options, see {@see \WpOrg\Requests\Requests::response()} for documentation
 	 */
 	protected function setup_handle($url, $headers, $data, $options) {
 		$options['hooks']->dispatch('curl.before_request', array(&$this->handle));
@@ -441,7 +451,7 @@ protected function setup_handle($url, $headers, $data, $options) {
 	 * @param string $response Response data from the body
 	 * @param array $options Request options
 	 * @return string|false HTTP response data including headers. False if non-blocking.
-	 * @throws Requests_Exception
+	 * @throws \WpOrg\Requests\Exception
 	 */
 	public function process_response($response, $options) {
 		if ($options['blocking'] === false) {
@@ -463,7 +473,7 @@ public function process_response($response, $options) {
 				curl_errno($this->handle),
 				curl_error($this->handle)
 			);
-			throw new Requests_Exception($error, 'curlerror', $this->handle);
+			throw new Exception($error, 'curlerror', $this->handle);
 		}
 		$this->info = curl_getinfo($this->handle);
 
diff --git a/library/Requests/Transport/fsockopen.php b/src/Transport/Fsockopen.php
similarity index 87%
rename from library/Requests/Transport/fsockopen.php
rename to src/Transport/Fsockopen.php
index 2927e5dc8..fe7335dc8 100644
--- a/library/Requests/Transport/fsockopen.php
+++ b/src/Transport/Fsockopen.php
@@ -6,13 +6,22 @@
  * @subpackage Transport
  */
 
+namespace WpOrg\Requests\Transport;
+
+use WpOrg\Requests\Exception;
+use WpOrg\Requests\Exception\InvalidArgument;
+use WpOrg\Requests\Requests;
+use WpOrg\Requests\Ssl;
+use WpOrg\Requests\Transport;
+use WpOrg\Requests\Utility\CaseInsensitiveDictionary;
+
 /**
  * fsockopen HTTP transport
  *
  * @package Requests
  * @subpackage Transport
  */
-class Requests_Transport_fsockopen implements Requests_Transport {
+class Fsockopen implements Transport {
 	/**
 	 * Second to microsecond conversion
 	 *
@@ -46,13 +55,13 @@ class Requests_Transport_fsockopen implements Requests_Transport {
 	/**
 	 * Perform a request
 	 *
-	 * @throws Requests_Exception On failure to connect to socket (`fsockopenerror`)
-	 * @throws Requests_Exception On socket timeout (`timeout`)
+	 * @throws \WpOrg\Requests\Exception On failure to connect to socket (`fsockopenerror`)
+	 * @throws \WpOrg\Requests\Exception On socket timeout (`timeout`)
 	 *
 	 * @param string $url URL to request
 	 * @param array $headers Associative array of request headers
 	 * @param string|array $data Data to send either as the POST body, or as parameters in the URL for a GET/HEAD
-	 * @param array $options Request options, see {@see Requests::response()} for documentation
+	 * @param array $options Request options, see {@see \WpOrg\Requests\Requests::response()} for documentation
 	 * @return string Raw HTTP result
 	 */
 	public function request($url, $headers = array(), $data = array(), $options = array()) {
@@ -62,7 +71,7 @@ public function request($url, $headers = array(), $data = array(), $options = ar
 			} elseif (is_int($data) || is_float($data)) {
 				$data = (string) $data;
 			} else {
-				throw new Requests_Exception_InvalidArgument(
+				throw new InvalidArgument(
 					sprintf(
 						'%s: Argument #%d (%s) must be of type %s, %s given',
 						__METHOD__,
@@ -79,12 +88,12 @@ public function request($url, $headers = array(), $data = array(), $options = ar
 
 		$url_parts = parse_url($url);
 		if (empty($url_parts)) {
-			throw new Requests_Exception('Invalid URL.', 'invalidurl', $url);
+			throw new Exception('Invalid URL.', 'invalidurl', $url);
 		}
 		$host                     = $url_parts['host'];
 		$context                  = stream_context_create();
 		$verifyname               = false;
-		$case_insensitive_headers = new Requests_Utility_CaseInsensitiveDictionary($headers);
+		$case_insensitive_headers = new CaseInsensitiveDictionary($headers);
 
 		// HTTPS support
 		if (isset($url_parts['scheme']) && strtolower($url_parts['scheme']) === 'https') {
@@ -147,16 +156,16 @@ public function request($url, $headers = array(), $data = array(), $options = ar
 		restore_error_handler();
 
 		if ($verifyname && !$this->verify_certificate_from_context($host, $context)) {
-			throw new Requests_Exception('SSL certificate did not match the requested domain name', 'ssl.no_match');
+			throw new Exception('SSL certificate did not match the requested domain name', 'ssl.no_match');
 		}
 
 		if (!$socket) {
 			if ($errno === 0) {
 				// Connection issue
-				throw new Requests_Exception(rtrim($this->connect_error), 'fsockopen.connect_error');
+				throw new Exception(rtrim($this->connect_error), 'fsockopen.connect_error');
 			}
 
-			throw new Requests_Exception($errstr, 'fsockopenerror', null, $errno);
+			throw new Exception($errstr, 'fsockopenerror', null, $errno);
 		}
 
 		$data_format = $options['data_format'];
@@ -264,14 +273,14 @@ public function request($url, $headers = array(), $data = array(), $options = ar
 			$download = @fopen($options['filename'], 'wb');
 			if ($download === false) {
 				$error = error_get_last();
-				throw new Requests_Exception($error['message'], 'fopen');
+				throw new Exception($error['message'], 'fopen');
 			}
 		}
 
 		while (!feof($socket)) {
 			$this->info = stream_get_meta_data($socket);
 			if ($this->info['timed_out']) {
-				throw new Requests_Exception('fsocket timed out', 'timeout');
+				throw new Exception('fsocket timed out', 'timeout');
 			}
 
 			$block = fread($socket, Requests::BUFFER_SIZE);
@@ -325,9 +334,9 @@ public function request($url, $headers = array(), $data = array(), $options = ar
 	/**
 	 * Send multiple requests simultaneously
 	 *
-	 * @param array $requests Request data (array of 'url', 'headers', 'data', 'options') as per {@see Requests_Transport::request}
-	 * @param array $options Global options, see {@see Requests::response()} for documentation
-	 * @return array Array of Requests_Response objects (may contain Requests_Exception or string responses as well)
+	 * @param array $requests Request data (array of 'url', 'headers', 'data', 'options') as per {@see \WpOrg\Requests\Transport::request}
+	 * @param array $options Global options, see {@see \WpOrg\Requests\Requests::response()} for documentation
+	 * @return array Array of \WpOrg\Requests\Response objects (may contain \WpOrg\Requests\Exception or string responses as well)
 	 */
 	public function request_multiple($requests, $options) {
 		$responses = array();
@@ -339,7 +348,7 @@ public function request_multiple($requests, $options) {
 
 				$request['options']['hooks']->dispatch('transport.internal.parse_response', array(&$responses[$id], $request));
 			}
-			catch (Requests_Exception $e) {
+			catch (Exception $e) {
 				$responses[$id] = $e;
 			}
 
@@ -427,8 +436,8 @@ public function connect_error_handler($errno, $errstr) {
 	 *
 	 * @see https://tools.ietf.org/html/rfc2818#section-3.1 RFC2818, Section 3.1
 	 *
-	 * @throws Requests_Exception On failure to connect via TLS (`fsockopen.ssl.connect_error`)
-	 * @throws Requests_Exception On not obtaining a match for the host (`fsockopen.ssl.no_match`)
+	 * @throws \WpOrg\Requests\Exception On failure to connect via TLS (`fsockopen.ssl.connect_error`)
+	 * @throws \WpOrg\Requests\Exception On not obtaining a match for the host (`fsockopen.ssl.no_match`)
 	 * @param string $host Host name to verify against
 	 * @param resource $context Stream context
 	 * @return bool
@@ -439,12 +448,12 @@ public function verify_certificate_from_context($host, $context) {
 		// If we don't have SSL options, then we couldn't make the connection at
 		// all
 		if (empty($meta) || empty($meta['ssl']) || empty($meta['ssl']['peer_certificate'])) {
-			throw new Requests_Exception(rtrim($this->connect_error), 'ssl.connect_error');
+			throw new Exception(rtrim($this->connect_error), 'ssl.connect_error');
 		}
 
 		$cert = openssl_x509_parse($meta['ssl']['peer_certificate']);
 
-		return Requests_SSL::verify_certificate($host, $cert);
+		return Ssl::verify_certificate($host, $cert);
 	}
 
 	/**
diff --git a/library/Requests/Transport/cacert.pem b/src/Transport/cacert.pem
similarity index 100%
rename from library/Requests/Transport/cacert.pem
rename to src/Transport/cacert.pem
diff --git a/library/Requests/Utility/CaseInsensitiveDictionary.php b/src/Utility/CaseInsensitiveDictionary.php
similarity index 81%
rename from library/Requests/Utility/CaseInsensitiveDictionary.php
rename to src/Utility/CaseInsensitiveDictionary.php
index bf850c46c..738944d8c 100644
--- a/library/Requests/Utility/CaseInsensitiveDictionary.php
+++ b/src/Utility/CaseInsensitiveDictionary.php
@@ -6,13 +6,21 @@
  * @subpackage Utilities
  */
 
+namespace WpOrg\Requests\Utility;
+
+use ArrayAccess;
+use ArrayIterator;
+use IteratorAggregate;
+use ReturnTypeWillChange;
+use WpOrg\Requests\Exception;
+
 /**
  * Case-insensitive dictionary, suitable for HTTP headers
  *
  * @package Requests
  * @subpackage Utilities
  */
-class Requests_Utility_CaseInsensitiveDictionary implements ArrayAccess, IteratorAggregate {
+class CaseInsensitiveDictionary implements ArrayAccess, IteratorAggregate {
 	/**
 	 * Actual item data
 	 *
@@ -62,7 +70,7 @@ public function offsetGet($key) {
 	/**
 	 * Set the given item
 	 *
-	 * @throws Requests_Exception On attempting to use dictionary as list (`invalidset`)
+	 * @throws \WpOrg\Requests\Exception On attempting to use dictionary as list (`invalidset`)
 	 *
 	 * @param string $key Item name
 	 * @param string $value Item value
@@ -70,7 +78,7 @@ public function offsetGet($key) {
 	#[ReturnTypeWillChange]
 	public function offsetSet($key, $value) {
 		if ($key === null) {
-			throw new Requests_Exception('Object is a dictionary, not a list', 'invalidset');
+			throw new Exception('Object is a dictionary, not a list', 'invalidset');
 		}
 
 		$key              = strtolower($key);
@@ -90,7 +98,7 @@ public function offsetUnset($key) {
 	/**
 	 * Get an iterator for the data
 	 *
-	 * @return ArrayIterator
+	 * @return \ArrayIterator
 	 */
 	#[ReturnTypeWillChange]
 	public function getIterator() {
diff --git a/library/Requests/Utility/FilteredIterator.php b/src/Utility/FilteredIterator.php
similarity index 90%
rename from library/Requests/Utility/FilteredIterator.php
rename to src/Utility/FilteredIterator.php
index 81a431b69..e34955767 100644
--- a/library/Requests/Utility/FilteredIterator.php
+++ b/src/Utility/FilteredIterator.php
@@ -6,13 +6,18 @@
  * @subpackage Utilities
  */
 
+namespace WpOrg\Requests\Utility;
+
+use ArrayIterator;
+use ReturnTypeWillChange;
+
 /**
  * Iterator for arrays requiring filtered values
  *
  * @package Requests
  * @subpackage Utilities
  */
-class Requests_Utility_FilteredIterator extends ArrayIterator {
+class FilteredIterator extends ArrayIterator {
 	/**
 	 * Callback to run as a filter
 	 *
diff --git a/tests/Auth/BasicTest.php b/tests/Auth/BasicTest.php
index 80b315c9e..3714062e4 100644
--- a/tests/Auth/BasicTest.php
+++ b/tests/Auth/BasicTest.php
@@ -1,19 +1,19 @@
 <?php
 
-namespace Requests\Tests\Auth;
+namespace WpOrg\Requests\Tests\Auth;
 
-use Requests;
-use Requests\Tests\TestCase;
-use Requests_Auth_Basic;
-use Requests_Exception;
-use Requests_Transport_cURL;
-use Requests_Transport_fsockopen;
+use WpOrg\Requests\Auth\Basic;
+use WpOrg\Requests\Exception;
+use WpOrg\Requests\Requests;
+use WpOrg\Requests\Tests\TestCase;
+use WpOrg\Requests\Transport\Curl;
+use WpOrg\Requests\Transport\Fsockopen;
 
 class BasicTest extends TestCase {
 	public static function transportProvider() {
 		return array(
-			array(Requests_Transport_fsockopen::class),
-			array(Requests_Transport_cURL::class),
+			array(Fsockopen::class),
+			array(Curl::class),
 		);
 	}
 
@@ -48,7 +48,7 @@ public function testUsingInstantiation($transport) {
 		}
 
 		$options = array(
-			'auth'      => new Requests_Auth_Basic(array('user', 'passwd')),
+			'auth'      => new Basic(array('user', 'passwd')),
 			'transport' => $transport,
 		);
 		$request = Requests::get(httpbin('/basic-auth/user/passwd'), array(), $options);
@@ -69,7 +69,7 @@ public function testPOSTUsingInstantiation($transport) {
 		}
 
 		$options = array(
-			'auth'      => new Requests_Auth_Basic(array('user', 'passwd')),
+			'auth'      => new Basic(array('user', 'passwd')),
 			'transport' => $transport,
 		);
 		$data    = 'test';
@@ -86,9 +86,9 @@ public function testPOSTUsingInstantiation($transport) {
 	}
 
 	public function testMissingPassword() {
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('Invalid number of arguments');
-		new Requests_Auth_Basic(array('user'));
+		new Basic(array('user'));
 	}
 
 }
diff --git a/tests/AutoloadTest.php b/tests/AutoloadTest.php
new file mode 100644
index 000000000..dc94924de
--- /dev/null
+++ b/tests/AutoloadTest.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace WpOrg\Requests\Tests;
+
+use Requests_Exception_Transport_cURL;
+use WpOrg\Requests\Tests\TestCase;
+
+class AutoloadTest extends TestCase {
+
+	const MSG = 'The PSR-0 `Requests_...` class names in the Request library are deprecated.';
+
+	/**
+	 * Verify that a deprecation notice is thrown when the "old" Requests class is loaded.
+	 */
+	public function testDeprecationNoticeThrownForOldRequestsClass() {
+		$this->expectDeprecation();
+		$this->expectDeprecationMessage(self::MSG);
+
+		require_once dirname(__DIR__) . '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/library/Requests.php';
+	}
+
+	/**
+	 * Verify that a deprecation notice is thrown when one of the other "old" Requests classes is autoloaded.
+	 */
+	public function testDeprecationNoticeThrownForOtherOldRequestsClass() {
+		$this->expectDeprecation();
+		$this->expectDeprecationMessage(self::MSG);
+
+		$this->assertSame('cURLEasy', Requests_Exception_Transport_cURL::EASY);
+	}
+}
diff --git a/tests/ChunkedEncodingTest.php b/tests/ChunkedEncodingTest.php
index f890c8b06..3e1b218b9 100644
--- a/tests/ChunkedEncodingTest.php
+++ b/tests/ChunkedEncodingTest.php
@@ -1,10 +1,10 @@
 <?php
 
-namespace Requests\Tests;
+namespace WpOrg\Requests\Tests;
 
-use Requests;
-use Requests\Tests\Mock\TransportMock;
-use Requests\Tests\TestCase;
+use WpOrg\Requests\Requests;
+use WpOrg\Requests\Tests\Mock\TransportMock;
+use WpOrg\Requests\Tests\TestCase;
 
 class ChunkedDecodingTest extends TestCase {
 	public static function chunkedProvider() {
diff --git a/tests/CookiesTest.php b/tests/CookiesTest.php
index 24655544a..fe61a9ea8 100644
--- a/tests/CookiesTest.php
+++ b/tests/CookiesTest.php
@@ -1,19 +1,19 @@
 <?php
 
-namespace Requests\Tests;
+namespace WpOrg\Requests\Tests;
 
-use Requests;
-use Requests\Tests\TestCase;
-use Requests_Cookie;
-use Requests_Cookie_Jar;
-use Requests_Exception;
-use Requests_IRI;
-use Requests_Response_Headers;
-use Requests_Utility_CaseInsensitiveDictionary;
+use WpOrg\Requests\Cookie;
+use WpOrg\Requests\Cookie\Jar;
+use WpOrg\Requests\Exception;
+use WpOrg\Requests\Iri;
+use WpOrg\Requests\Requests;
+use WpOrg\Requests\Response\Headers;
+use WpOrg\Requests\Tests\TestCase;
+use WpOrg\Requests\Utility\CaseInsensitiveDictionary;
 
 class CookiesTest extends TestCase {
 	public function testBasicCookie() {
-		$cookie = new Requests_Cookie('requests-testcookie', 'testvalue');
+		$cookie = new Cookie('requests-testcookie', 'testvalue');
 
 		$this->assertSame('requests-testcookie', $cookie->name);
 		$this->assertSame('testvalue', $cookie->value);
@@ -28,28 +28,28 @@ public function testCookieWithAttributes() {
 			'httponly',
 			'path' => '/',
 		);
-		$cookie     = new Requests_Cookie('requests-testcookie', 'testvalue', $attributes);
+		$cookie     = new Cookie('requests-testcookie', 'testvalue', $attributes);
 
 		$this->assertSame('requests-testcookie=testvalue', $cookie->format_for_header());
 		$this->assertSame('requests-testcookie=testvalue; httponly; path=/', $cookie->format_for_set_cookie());
 	}
 
 	public function testEmptyCookieName() {
-		$cookie = Requests_Cookie::parse('test');
+		$cookie = Cookie::parse('test');
 		$this->assertSame('', $cookie->name);
 		$this->assertSame('test', $cookie->value);
 	}
 
 	public function testEmptyAttributes() {
-		$cookie = Requests_Cookie::parse('foo=bar; HttpOnly');
+		$cookie = Cookie::parse('foo=bar; HttpOnly');
 		$this->assertTrue($cookie->attributes['httponly']);
 	}
 
 	public function testCookieJarSetter() {
-		$jar1                        = new Requests_Cookie_Jar();
+		$jar1                        = new Jar();
 		$jar1['requests-testcookie'] = 'testvalue';
 
-		$jar2 = new Requests_Cookie_Jar(
+		$jar2 = new Jar(
 			array(
 				'requests-testcookie' => 'testvalue',
 			)
@@ -58,7 +58,7 @@ public function testCookieJarSetter() {
 	}
 
 	public function testCookieJarUnsetter() {
-		$jar                        = new Requests_Cookie_Jar();
+		$jar                        = new Jar();
 		$jar['requests-testcookie'] = 'testvalue';
 
 		$this->assertSame('testvalue', $jar['requests-testcookie']);
@@ -69,9 +69,9 @@ public function testCookieJarUnsetter() {
 	}
 
 	public function testCookieJarAsList() {
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('Object is a dictionary, not a list');
-		$cookies   = new Requests_Cookie_Jar();
+		$cookies   = new Jar();
 		$cookies[] = 'requests-testcookie1=testvalue1';
 	}
 
@@ -80,7 +80,7 @@ public function testCookieJarIterator() {
 			'requests-testcookie1' => 'testvalue1',
 			'requests-testcookie2' => 'testvalue2',
 		);
-		$jar     = new Requests_Cookie_Jar($cookies);
+		$jar     = new Jar($cookies);
 
 		foreach ($jar as $key => $value) {
 			$this->assertSame($cookies[$key], $value);
@@ -154,7 +154,7 @@ public function testCookieExpiration() {
 	}
 
 	public function testSendingCookieWithJar() {
-		$cookies = new Requests_Cookie_Jar(
+		$cookies = new Jar(
 			array(
 				'requests-testcookie1' => 'testvalue1',
 			)
@@ -180,7 +180,7 @@ public function testSendingMultipleCookies() {
 	}
 
 	public function testSendingMultipleCookiesWithJar() {
-		$cookies = new Requests_Cookie_Jar(
+		$cookies = new Jar(
 			array(
 				'requests-testcookie1' => 'testvalue1',
 				'requests-testcookie2' => 'testvalue2',
@@ -196,9 +196,9 @@ public function testSendingMultipleCookiesWithJar() {
 	}
 
 	public function testSendingPrebakedCookie() {
-		$cookies = new Requests_Cookie_Jar(
+		$cookies = new Jar(
 			array(
-				new Requests_Cookie('requests-testcookie', 'testvalue'),
+				new Cookie('requests-testcookie', 'testvalue'),
 			)
 		);
 		$data    = $this->setCookieRequest($cookies);
@@ -236,9 +236,9 @@ public function domainMatchProvider() {
 	 * @dataProvider domainMatchProvider
 	 */
 	public function testDomainExactMatch($original, $check, $matches, $domain_matches) {
-		$attributes           = new Requests_Utility_CaseInsensitiveDictionary();
+		$attributes           = new CaseInsensitiveDictionary();
 		$attributes['domain'] = $original;
-		$cookie               = new Requests_Cookie('requests-testcookie', 'testvalue', $attributes);
+		$cookie               = new Cookie('requests-testcookie', 'testvalue', $attributes);
 		$this->assertSame($matches, $cookie->domain_matches($check));
 	}
 
@@ -246,12 +246,12 @@ public function testDomainExactMatch($original, $check, $matches, $domain_matche
 	 * @dataProvider domainMatchProvider
 	 */
 	public function testDomainMatch($original, $check, $matches, $domain_matches) {
-		$attributes           = new Requests_Utility_CaseInsensitiveDictionary();
+		$attributes           = new CaseInsensitiveDictionary();
 		$attributes['domain'] = $original;
 		$flags                = array(
 			'host-only' => false,
 		);
-		$cookie               = new Requests_Cookie('requests-testcookie', 'testvalue', $attributes, $flags);
+		$cookie               = new Cookie('requests-testcookie', 'testvalue', $attributes, $flags);
 		$this->assertSame($domain_matches, $cookie->domain_matches($check));
 	}
 
@@ -279,9 +279,9 @@ public function pathMatchProvider() {
 	 * @dataProvider pathMatchProvider
 	 */
 	public function testPathMatch($original, $check, $matches) {
-		$attributes         = new Requests_Utility_CaseInsensitiveDictionary();
+		$attributes         = new CaseInsensitiveDictionary();
 		$attributes['path'] = $original;
-		$cookie             = new Requests_Cookie('requests-testcookie', 'testvalue', $attributes);
+		$cookie             = new Cookie('requests-testcookie', 'testvalue', $attributes);
 		$this->assertSame($matches, $cookie->path_matches($check));
 	}
 
@@ -318,11 +318,11 @@ public function urlMatchProvider() {
 	 * @dataProvider urlMatchProvider
 	 */
 	public function testUrlExactMatch($domain, $path, $check, $matches, $domain_matches) {
-		$attributes           = new Requests_Utility_CaseInsensitiveDictionary();
+		$attributes           = new CaseInsensitiveDictionary();
 		$attributes['domain'] = $domain;
 		$attributes['path']   = $path;
-		$check                = new Requests_IRI($check);
-		$cookie               = new Requests_Cookie('requests-testcookie', 'testvalue', $attributes);
+		$check                = new Iri($check);
+		$cookie               = new Cookie('requests-testcookie', 'testvalue', $attributes);
 		$this->assertSame($matches, $cookie->uri_matches($check));
 	}
 
@@ -332,33 +332,33 @@ public function testUrlExactMatch($domain, $path, $check, $matches, $domain_matc
 	 * @dataProvider urlMatchProvider
 	 */
 	public function testUrlMatch($domain, $path, $check, $matches, $domain_matches) {
-		$attributes           = new Requests_Utility_CaseInsensitiveDictionary();
+		$attributes           = new CaseInsensitiveDictionary();
 		$attributes['domain'] = $domain;
 		$attributes['path']   = $path;
 		$flags                = array(
 			'host-only' => false,
 		);
-		$check                = new Requests_IRI($check);
-		$cookie               = new Requests_Cookie('requests-testcookie', 'testvalue', $attributes, $flags);
+		$check                = new Iri($check);
+		$cookie               = new Cookie('requests-testcookie', 'testvalue', $attributes, $flags);
 		$this->assertSame($domain_matches, $cookie->uri_matches($check));
 	}
 
 	public function testUrlMatchSecure() {
-		$attributes           = new Requests_Utility_CaseInsensitiveDictionary();
+		$attributes           = new CaseInsensitiveDictionary();
 		$attributes['domain'] = 'example.com';
 		$attributes['path']   = '/';
 		$attributes['secure'] = true;
 		$flags                = array(
 			'host-only' => false,
 		);
-		$cookie               = new Requests_Cookie('requests-testcookie', 'testvalue', $attributes, $flags);
+		$cookie               = new Cookie('requests-testcookie', 'testvalue', $attributes, $flags);
 
-		$this->assertTrue($cookie->uri_matches(new Requests_IRI('https://example.com/')));
-		$this->assertFalse($cookie->uri_matches(new Requests_IRI('http://example.com/')));
+		$this->assertTrue($cookie->uri_matches(new Iri('https://example.com/')));
+		$this->assertFalse($cookie->uri_matches(new Iri('http://example.com/')));
 
 		// Double-check host-only
-		$this->assertTrue($cookie->uri_matches(new Requests_IRI('https://www.example.com/')));
-		$this->assertFalse($cookie->uri_matches(new Requests_IRI('http://www.example.com/')));
+		$this->assertTrue($cookie->uri_matches(new Iri('https://www.example.com/')));
+		$this->assertFalse($cookie->uri_matches(new Iri('http://www.example.com/')));
 	}
 
 	/**
@@ -369,18 +369,18 @@ public function testUrlMatchSecure() {
 	 * should be regarded as "global" cookies (that is, set for `.`)
 	 */
 	public function testUrlMatchManuallySet() {
-		$cookie = new Requests_Cookie('requests-testcookie', 'testvalue');
+		$cookie = new Cookie('requests-testcookie', 'testvalue');
 		$this->assertTrue($cookie->domain_matches('example.com'));
 		$this->assertTrue($cookie->domain_matches('example.net'));
 		$this->assertTrue($cookie->path_matches('/'));
 		$this->assertTrue($cookie->path_matches('/test'));
 		$this->assertTrue($cookie->path_matches('/test/'));
-		$this->assertTrue($cookie->uri_matches(new Requests_IRI('http://example.com/')));
-		$this->assertTrue($cookie->uri_matches(new Requests_IRI('http://example.com/test')));
-		$this->assertTrue($cookie->uri_matches(new Requests_IRI('http://example.com/test/')));
-		$this->assertTrue($cookie->uri_matches(new Requests_IRI('http://example.net/')));
-		$this->assertTrue($cookie->uri_matches(new Requests_IRI('http://example.net/test')));
-		$this->assertTrue($cookie->uri_matches(new Requests_IRI('http://example.net/test/')));
+		$this->assertTrue($cookie->uri_matches(new Iri('http://example.com/')));
+		$this->assertTrue($cookie->uri_matches(new Iri('http://example.com/test')));
+		$this->assertTrue($cookie->uri_matches(new Iri('http://example.com/test/')));
+		$this->assertTrue($cookie->uri_matches(new Iri('http://example.net/')));
+		$this->assertTrue($cookie->uri_matches(new Iri('http://example.net/test')));
+		$this->assertTrue($cookie->uri_matches(new Iri('http://example.net/test/')));
 	}
 
 	public static function parseResultProvider() {
@@ -495,7 +495,7 @@ public function testParsingHeader($header, $expected, $expected_attributes = arr
 		// Set the reference time to 2014-01-01 00:00:00
 		$reference_time = gmmktime(0, 0, 0, 1, 1, 2014);
 
-		$cookie = Requests_Cookie::parse($header, null, $reference_time);
+		$cookie = Cookie::parse($header, null, $reference_time);
 		$this->check_parsed_cookie($cookie, $expected, $expected_attributes);
 	}
 
@@ -508,7 +508,7 @@ public function testParsingHeaderDouble($header, $expected, $expected_attributes
 		// Set the reference time to 2014-01-01 00:00:00
 		$reference_time = gmmktime(0, 0, 0, 1, 1, 2014);
 
-		$cookie = Requests_Cookie::parse($header, null, $reference_time);
+		$cookie = Cookie::parse($header, null, $reference_time);
 
 		// Normalize the value again
 		$cookie->normalize();
@@ -520,13 +520,13 @@ public function testParsingHeaderDouble($header, $expected, $expected_attributes
 	 * @dataProvider parseResultProvider
 	 */
 	public function testParsingHeaderObject($header, $expected, $expected_attributes = array(), $expected_flags = array()) {
-		$headers               = new Requests_Response_Headers();
+		$headers               = new Headers();
 		$headers['Set-Cookie'] = $header;
 
 		// Set the reference time to 2014-01-01 00:00:00
 		$reference_time = gmmktime(0, 0, 0, 1, 1, 2014);
 
-		$parsed = Requests_Cookie::parse_from_headers($headers, null, $reference_time);
+		$parsed = Cookie::parse_from_headers($headers, null, $reference_time);
 		$this->assertCount(1, $parsed);
 
 		$cookie = reset($parsed);
@@ -647,14 +647,14 @@ public function parseFromHeadersProvider() {
 	 * @dataProvider parseFromHeadersProvider
 	 */
 	public function testParsingHeaderWithOrigin($header, $origin, $expected, $expected_attributes = array(), $expected_flags = array()) {
-		$origin                = new Requests_IRI($origin);
-		$headers               = new Requests_Response_Headers();
+		$origin                = new Iri($origin);
+		$headers               = new Headers();
 		$headers['Set-Cookie'] = $header;
 
 		// Set the reference time to 2014-01-01 00:00:00
 		$reference_time = gmmktime(0, 0, 0, 1, 1, 2014);
 
-		$parsed = Requests_Cookie::parse_from_headers($headers, $origin, $reference_time);
+		$parsed = Cookie::parse_from_headers($headers, $origin, $reference_time);
 		if (isset($expected['invalid'])) {
 			$this->assertCount(0, $parsed);
 			return;
diff --git a/tests/EncodingTest.php b/tests/EncodingTest.php
index 74d2a65ac..8c2573afb 100644
--- a/tests/EncodingTest.php
+++ b/tests/EncodingTest.php
@@ -1,9 +1,9 @@
 <?php
 
-namespace Requests\Tests;
+namespace WpOrg\Requests\Tests;
 
-use Requests;
-use Requests\Tests\TestCase;
+use WpOrg\Requests\Requests;
+use WpOrg\Requests\Tests\TestCase;
 
 class EncodingTest extends TestCase {
 	protected static function mapData($type, $data) {
diff --git a/tests/IDNAEncoderTest.php b/tests/IdnaEncoderTest.php
similarity index 59%
rename from tests/IDNAEncoderTest.php
rename to tests/IdnaEncoderTest.php
index 5dd851d99..385062907 100644
--- a/tests/IDNAEncoderTest.php
+++ b/tests/IdnaEncoderTest.php
@@ -1,12 +1,12 @@
 <?php
 
-namespace Requests\Tests;
+namespace WpOrg\Requests\Tests;
 
-use Requests\Tests\TestCase;
-use Requests_Exception;
-use Requests_IDNAEncoder;
+use WpOrg\Requests\Exception;
+use WpOrg\Requests\IdnaEncoder;
+use WpOrg\Requests\Tests\TestCase;
 
-class IDNAEncoderTest extends TestCase {
+class IdnaEncoderTest extends TestCase {
 	public static function specExamples() {
 		return array(
 			array(
@@ -24,77 +24,77 @@ public static function specExamples() {
 	 * @dataProvider specExamples
 	 */
 	public function testEncoding($data, $expected) {
-		$result = Requests_IDNAEncoder::encode($data);
+		$result = IdnaEncoder::encode($data);
 		$this->assertSame($expected, $result);
 	}
 
 	public function testASCIITooLong() {
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('Provided string is too long');
 		$data = str_repeat('abcd', 20);
-		Requests_IDNAEncoder::encode($data);
+		IdnaEncoder::encode($data);
 	}
 
 	public function testEncodedTooLong() {
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('Encoded string is too long');
 		$data = str_repeat("\xe4\xbb\x96", 60);
-		Requests_IDNAEncoder::encode($data);
+		IdnaEncoder::encode($data);
 	}
 
 	public function testAlreadyPrefixed() {
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('Provided string begins with ACE prefix');
-		Requests_IDNAEncoder::encode("xn--\xe4\xbb\x96");
+		IdnaEncoder::encode("xn--\xe4\xbb\x96");
 	}
 
 	public function testASCIICharacter() {
-		$result = Requests_IDNAEncoder::encode('a');
+		$result = IdnaEncoder::encode('a');
 		$this->assertSame('a', $result);
 	}
 
 	public function testTwoByteCharacter() {
-		$result = Requests_IDNAEncoder::encode("\xc2\xb6"); // Pilcrow character
+		$result = IdnaEncoder::encode("\xc2\xb6"); // Pilcrow character
 		$this->assertSame('xn--tba', $result);
 	}
 
 	public function testThreeByteCharacter() {
-		$result = Requests_IDNAEncoder::encode("\xe2\x82\xac"); // Euro symbol
+		$result = IdnaEncoder::encode("\xe2\x82\xac"); // Euro symbol
 		$this->assertSame('xn--lzg', $result);
 	}
 
 	public function testFourByteCharacter() {
-		$result = Requests_IDNAEncoder::encode("\xf0\xa4\xad\xa2"); // Chinese symbol?
+		$result = IdnaEncoder::encode("\xf0\xa4\xad\xa2"); // Chinese symbol?
 		$this->assertSame('xn--ww6j', $result);
 	}
 
 	public function testFiveByteCharacter() {
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('Invalid Unicode codepoint');
-		Requests_IDNAEncoder::encode("\xfb\xb6\xb6\xb6\xb6");
+		IdnaEncoder::encode("\xfb\xb6\xb6\xb6\xb6");
 	}
 
 	public function testSixByteCharacter() {
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('Invalid Unicode codepoint');
-		Requests_IDNAEncoder::encode("\xfd\xb6\xb6\xb6\xb6\xb6");
+		IdnaEncoder::encode("\xfd\xb6\xb6\xb6\xb6\xb6");
 	}
 
 	public function testInvalidASCIICharacterWithMultibyte() {
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('Invalid Unicode codepoint');
-		Requests_IDNAEncoder::encode("\0\xc2\xb6");
+		IdnaEncoder::encode("\0\xc2\xb6");
 	}
 
 	public function testUnfinishedMultibyte() {
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('Invalid Unicode codepoint');
-		Requests_IDNAEncoder::encode("\xc2");
+		IdnaEncoder::encode("\xc2");
 	}
 
 	public function testPartialMultibyte() {
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('Invalid Unicode codepoint');
-		Requests_IDNAEncoder::encode("\xc2\xc2\xb6");
+		IdnaEncoder::encode("\xc2\xc2\xb6");
 	}
 }
diff --git a/tests/IRITest.php b/tests/IriTest.php
similarity index 87%
rename from tests/IRITest.php
rename to tests/IriTest.php
index a0662929f..ea43c2f5a 100644
--- a/tests/IRITest.php
+++ b/tests/IriTest.php
@@ -40,12 +40,12 @@
  *
  */
 
-namespace Requests\Tests;
+namespace WpOrg\Requests\Tests;
 
-use Requests_IRI;
-use Requests\Tests\TestCase;
+use WpOrg\Requests\Iri;
+use WpOrg\Requests\Tests\TestCase;
 
-class IRITest extends TestCase
+class IriTest extends TestCase
 {
 	public static function rfc3986_tests()
 	{
@@ -102,9 +102,9 @@ public static function rfc3986_tests()
 	 */
 	public function testStringRFC3986($relative, $expected)
 	{
-		$base = new Requests_IRI('http://a/b/c/d;p?q');
-		$this->assertSame($expected, Requests_IRI::absolutize($base, $relative)->iri);
-		$this->assertSame($expected, (string) Requests_IRI::absolutize($base, $relative));
+		$base = new Iri('http://a/b/c/d;p?q');
+		$this->assertSame($expected, Iri::absolutize($base, $relative)->iri);
+		$this->assertSame($expected, (string) Iri::absolutize($base, $relative));
 	}
 
 	/**
@@ -113,8 +113,8 @@ public function testStringRFC3986($relative, $expected)
 	public function testBothStringRFC3986($relative, $expected)
 	{
 		$base = 'http://a/b/c/d;p?q';
-		$this->assertSame($expected, Requests_IRI::absolutize($base, $relative)->iri);
-		$this->assertSame($expected, (string) Requests_IRI::absolutize($base, $relative));
+		$this->assertSame($expected, Iri::absolutize($base, $relative)->iri);
+		$this->assertSame($expected, (string) Iri::absolutize($base, $relative));
 	}
 
 	/**
@@ -122,9 +122,9 @@ public function testBothStringRFC3986($relative, $expected)
 	 */
 	public function testObjectRFC3986($relative, $expected)
 	{
-		$base = new Requests_IRI('http://a/b/c/d;p?q');
-		$expected = new Requests_IRI($expected);
-		$this->assertEquals($expected, Requests_IRI::absolutize($base, $relative));
+		$base = new Iri('http://a/b/c/d;p?q');
+		$expected = new Iri($expected);
+		$this->assertEquals($expected, Iri::absolutize($base, $relative));
 	}
 
 	public static function sp_tests()
@@ -154,9 +154,9 @@ public static function sp_tests()
 	 */
 	public function testStringSP($base, $relative, $expected)
 	{
-		$base = new Requests_IRI($base);
-		$this->assertSame($expected, Requests_IRI::absolutize($base, $relative)->iri);
-		$this->assertSame($expected, (string) Requests_IRI::absolutize($base, $relative));
+		$base = new Iri($base);
+		$this->assertSame($expected, Iri::absolutize($base, $relative)->iri);
+		$this->assertSame($expected, (string) Iri::absolutize($base, $relative));
 	}
 
 	/**
@@ -164,9 +164,9 @@ public function testStringSP($base, $relative, $expected)
 	 */
 	public function testObjectSP($base, $relative, $expected)
 	{
-		$base = new Requests_IRI($base);
-		$expected = new Requests_IRI($expected);
-		$this->assertEquals($expected, Requests_IRI::absolutize($base, $relative));
+		$base = new Iri($base);
+		$expected = new Iri($expected);
+		$this->assertEquals($expected, Iri::absolutize($base, $relative));
 	}
 
 	public static function absolutize_tests()
@@ -182,8 +182,8 @@ public static function absolutize_tests()
 	 */
 	public function testAbsolutizeString($base, $relative, $expected)
 	{
-		$base = new Requests_IRI($base);
-		$this->assertSame($expected, Requests_IRI::absolutize($base, $relative)->iri);
+		$base = new Iri($base);
+		$this->assertSame($expected, Iri::absolutize($base, $relative)->iri);
 	}
 
 	/**
@@ -191,9 +191,9 @@ public function testAbsolutizeString($base, $relative, $expected)
 	 */
 	public function testAbsolutizeObject($base, $relative, $expected)
 	{
-		$base = new Requests_IRI($base);
-		$expected = new Requests_IRI($expected);
-		$this->assertEquals($expected, Requests_IRI::absolutize($base, $relative));
+		$base = new Iri($base);
+		$expected = new Iri($expected);
+		$this->assertEquals($expected, Iri::absolutize($base, $relative));
 	}
 
 	public static function normalization_tests()
@@ -284,7 +284,7 @@ public static function normalization_tests()
 	 */
 	public function testStringNormalization($input, $output)
 	{
-		$input = new Requests_IRI($input);
+		$input = new Iri($input);
 		$this->assertSame($output, $input->iri);
 		$this->assertSame($output, (string) $input);
 	}
@@ -294,8 +294,8 @@ public function testStringNormalization($input, $output)
 	 */
 	public function testObjectNormalization($input, $output)
 	{
-		$input = new Requests_IRI($input);
-		$output = new Requests_IRI($output);
+		$input = new Iri($input);
+		$output = new Iri($output);
 		$this->assertEquals($output, $input);
 	}
 
@@ -311,8 +311,8 @@ public static function equivalence_tests()
 	 */
 	public function testObjectEquivalence($input, $output)
 	{
-		$input = new Requests_IRI($input);
-		$output = new Requests_IRI($output);
+		$input = new Iri($input);
+		$output = new Iri($output);
 		$this->assertEquals($output, $input);
 	}
 
@@ -328,19 +328,19 @@ public static function not_equivalence_tests()
 	 */
 	public function testObjectNotEquivalence($input, $output)
 	{
-		$input = new Requests_IRI($input);
-		$output = new Requests_IRI($output);
+		$input = new Iri($input);
+		$output = new Iri($output);
 		$this->assertNotEquals($output, $input);
 	}
 
 	public function testInvalidAbsolutizeBase()
 	{
-		$this->assertFalse(Requests_IRI::absolutize('://not a URL', '../'));
+		$this->assertFalse(Iri::absolutize('://not a URL', '../'));
 	}
 
 	public function testFullGamut()
 	{
-		$iri = new Requests_IRI();
+		$iri = new Iri();
 		$iri->scheme = 'http';
 		$iri->userinfo = 'user:password';
 		$iri->host = 'example.com';
@@ -357,7 +357,7 @@ public function testFullGamut()
 
 	public function testReadAliased()
 	{
-		$iri = new Requests_IRI();
+		$iri = new Iri();
 		$iri->scheme = 'http';
 		$iri->userinfo = 'user:password';
 		$iri->host = 'example.com';
@@ -374,7 +374,7 @@ public function testReadAliased()
 
 	public function testWriteAliased()
 	{
-		$iri = new Requests_IRI();
+		$iri = new Iri();
 		$iri->scheme = 'http';
 		$iri->iuserinfo = 'user:password';
 		$iri->ihost = 'example.com';
@@ -391,15 +391,15 @@ public function testWriteAliased()
 
 	public function testNonexistantProperty()
 	{
-		$this->expectNotice('Undefined property: Requests_IRI::nonexistant_prop');
-		$iri = new Requests_IRI();
+		$this->expectNotice('Undefined property: WpOrg\Requests\Iri::nonexistant_prop');
+		$iri = new Iri();
 		$this->assertFalse(isset($iri->nonexistant_prop));
 		$should_fail = $iri->nonexistant_prop;
 	}
 
 	public function testBlankHost()
 	{
-		$iri = new Requests_IRI('http://example.com/a/?b=c#d');
+		$iri = new Iri('http://example.com/a/?b=c#d');
 		$iri->host = null;
 
 		$this->assertNull($iri->host);
@@ -408,7 +408,7 @@ public function testBlankHost()
 
 	public function testBadPort()
 	{
-		$iri = new Requests_IRI();
+		$iri = new Iri();
 		$iri->port = 'example';
 
 		$this->assertNull($iri->port);
diff --git a/tests/Mock/RawTransportMock.php b/tests/Mock/RawTransportMock.php
index c807e01c9..19168dddd 100644
--- a/tests/Mock/RawTransportMock.php
+++ b/tests/Mock/RawTransportMock.php
@@ -1,10 +1,10 @@
 <?php
 
-namespace Requests\Tests\Mock;
+namespace WpOrg\Requests\Tests\Mock;
 
-use Requests_Transport;
+use WpOrg\Requests\Transport;
 
-class RawTransportMock implements Requests_Transport {
+class RawTransportMock implements Transport {
 	public $data = '';
 	public function request($url, $headers = array(), $data = array(), $options = array()) {
 		return $this->data;
diff --git a/tests/Mock/TransportMock.php b/tests/Mock/TransportMock.php
index a0af0a186..7702691bb 100644
--- a/tests/Mock/TransportMock.php
+++ b/tests/Mock/TransportMock.php
@@ -1,10 +1,10 @@
 <?php
 
-namespace Requests\Tests\Mock;
+namespace WpOrg\Requests\Tests\Mock;
 
-use Requests_Transport;
+use WpOrg\Requests\Transport;
 
-class TransportMock implements Requests_Transport {
+class TransportMock implements Transport {
 	public $code        = 200;
 	public $chunked     = false;
 	public $body        = 'Test Body';
diff --git a/tests/Proxy/HTTPTest.php b/tests/Proxy/HttpTest.php
similarity index 86%
rename from tests/Proxy/HTTPTest.php
rename to tests/Proxy/HttpTest.php
index b25e81471..938642634 100644
--- a/tests/Proxy/HTTPTest.php
+++ b/tests/Proxy/HttpTest.php
@@ -1,15 +1,15 @@
 <?php
 
-namespace Requests\Tests\Proxy;
+namespace WpOrg\Requests\Tests\Proxy;
 
-use Requests;
-use Requests\Tests\TestCase;
-use Requests_Exception;
-use Requests_Proxy_HTTP;
-use Requests_Transport_cURL;
-use Requests_Transport_fsockopen;
+use WpOrg\Requests\Exception;
+use WpOrg\Requests\Proxy\Http;
+use WpOrg\Requests\Requests;
+use WpOrg\Requests\Tests\TestCase;
+use WpOrg\Requests\Transport\Curl;
+use WpOrg\Requests\Transport\Fsockopen;
 
-class HTTPTest extends TestCase {
+class HttpTest extends TestCase {
 	protected function checkProxyAvailable($type = '') {
 		switch ($type) {
 			case 'auth':
@@ -28,8 +28,8 @@ protected function checkProxyAvailable($type = '') {
 
 	public function transportProvider() {
 		return array(
-			array(Requests_Transport_cURL::class),
-			array(Requests_Transport_fsockopen::class),
+			array(Curl::class),
+			array(Fsockopen::class),
 		);
 	}
 
@@ -77,7 +77,7 @@ public function testConnectInvalidParameters($transport) {
 			'proxy'     => array(REQUESTS_HTTP_PROXY, 'testuser', 'password', 'something'),
 			'transport' => $transport,
 		);
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('Invalid number of arguments');
 		Requests::get(httpbin('/get'), array(), $options);
 	}
@@ -89,7 +89,7 @@ public function testConnectWithInstance($transport) {
 		$this->checkProxyAvailable();
 
 		$options  = array(
-			'proxy'     => new Requests_Proxy_HTTP(REQUESTS_HTTP_PROXY),
+			'proxy'     => new Http(REQUESTS_HTTP_PROXY),
 			'transport' => $transport,
 		);
 		$response = Requests::get(httpbin('/get'), array(), $options);
@@ -137,10 +137,10 @@ public function testConnectWithInvalidAuth($transport) {
 		);
 
 		if (version_compare(phpversion(), '5.5.0', '>=') === true
-			&& $transport === Requests_Transport_fsockopen::class
+			&& $transport === Fsockopen::class
 		) {
 			// @TODO fsockopen connection times out on invalid auth instead of returning 407.
-			$this->expectException(Requests_Exception::class);
+			$this->expectException(Exception::class);
 			$this->expectExceptionMessage('fsocket timed out');
 		}
 
diff --git a/tests/RequestsTest.php b/tests/RequestsTest.php
index 849b7dac9..df012ce6e 100644
--- a/tests/RequestsTest.php
+++ b/tests/RequestsTest.php
@@ -1,18 +1,18 @@
 <?php
 
-namespace Requests\Tests;
+namespace WpOrg\Requests\Tests;
 
-use Requests;
-use Requests\Tests\Mock\RawTransportMock;
-use Requests\Tests\Mock\TransportMock;
-use Requests\Tests\TestCase;
-use Requests_Exception;
-use Requests_Response_Headers;
+use WpOrg\Requests\Exception;
+use WpOrg\Requests\Requests;
+use WpOrg\Requests\Response\Headers;
+use WpOrg\Requests\Tests\Mock\RawTransportMock;
+use WpOrg\Requests\Tests\Mock\TransportMock;
+use WpOrg\Requests\Tests\TestCase;
 
 class RequestsTest extends TestCase {
 
 	public function testInvalidProtocol() {
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('Only HTTP(S) requests are handled');
 		Requests::request('ftp://128.0.0.1/');
 	}
@@ -44,7 +44,7 @@ public function testHeaderParsing() {
 			'transport' => $transport,
 		);
 		$response              = Requests::get('http://example.com/', array(), $options);
-		$expected              = new Requests_Response_Headers();
+		$expected              = new Headers();
 		$expected['host']      = 'localhost,ambiguous';
 		$expected['nospace']   = 'here';
 		$expected['muchspace'] = 'there';
@@ -117,7 +117,7 @@ public function testInvalidProtocolVersion() {
 			'transport' => $transport,
 		);
 
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('Response could not be parsed');
 		Requests::get('http://example.com/', array(), $options);
 	}
@@ -133,7 +133,7 @@ public function testSingleCRLFSeparator() {
 			'transport' => $transport,
 		);
 
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('Missing header/body separator');
 		Requests::get('http://example.com/', array(), $options);
 	}
@@ -146,7 +146,7 @@ public function testInvalidStatus() {
 			'transport' => $transport,
 		);
 
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('Response could not be parsed');
 		Requests::get('http://example.com/', array(), $options);
 	}
@@ -165,7 +165,7 @@ public function test30xWithoutLocation() {
 
 	public function testTimeoutException() {
 		$options = array('timeout' => 0.5);
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('timed out');
 		Requests::get(httpbin('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/delay/3'), array(), $options);
 	}
diff --git a/tests/Response/HeadersTest.php b/tests/Response/HeadersTest.php
index 2e69e0803..f35058d9a 100644
--- a/tests/Response/HeadersTest.php
+++ b/tests/Response/HeadersTest.php
@@ -1,20 +1,20 @@
 <?php
 
-namespace Requests\Tests\Response;
+namespace WpOrg\Requests\Tests\Response;
 
-use Requests\Tests\TestCase;
-use Requests_Exception;
-use Requests_Response_Headers;
+use WpOrg\Requests\Exception;
+use WpOrg\Requests\Response\Headers;
+use WpOrg\Requests\Tests\TestCase;
 
 class HeadersTest extends TestCase {
 	public function testArrayAccess() {
-		$headers                 = new Requests_Response_Headers();
+		$headers                 = new Headers();
 		$headers['Content-Type'] = 'text/plain';
 
 		$this->assertSame('text/plain', $headers['Content-Type']);
 	}
 	public function testCaseInsensitiveArrayAccess() {
-		$headers                 = new Requests_Response_Headers();
+		$headers                 = new Headers();
 		$headers['Content-Type'] = 'text/plain';
 
 		$this->assertSame('text/plain', $headers['CONTENT-TYPE']);
@@ -25,7 +25,7 @@ public function testCaseInsensitiveArrayAccess() {
 	 * @depends testArrayAccess
 	 */
 	public function testIteration() {
-		$headers                   = new Requests_Response_Headers();
+		$headers                   = new Headers();
 		$headers['Content-Type']   = 'text/plain';
 		$headers['Content-Length'] = 10;
 
@@ -44,14 +44,14 @@ public function testIteration() {
 	}
 
 	public function testInvalidKey() {
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('Object is a dictionary, not a list');
-		$headers   = new Requests_Response_Headers();
+		$headers   = new Headers();
 		$headers[] = 'text/plain';
 	}
 
 	public function testMultipleHeaders() {
-		$headers           = new Requests_Response_Headers();
+		$headers           = new Headers();
 		$headers['Accept'] = 'text/html;q=1.0';
 		$headers['Accept'] = '*/*;q=0.1';
 
diff --git a/tests/SessionTest.php b/tests/SessionTest.php
index ecd637744..cd2ca260d 100644
--- a/tests/SessionTest.php
+++ b/tests/SessionTest.php
@@ -1,14 +1,14 @@
 <?php
 
-namespace Requests\Tests;
+namespace WpOrg\Requests\Tests;
 
-use Requests\Tests\TestCase;
-use Requests_Response;
-use Requests_Session;
+use WpOrg\Requests\Response;
+use WpOrg\Requests\Session;
+use WpOrg\Requests\Tests\TestCase;
 
 class SessionTest extends TestCase {
 	public function testURLResolution() {
-		$session = new Requests_Session(httpbin('/'));
+		$session = new Session(httpbin('/'));
 
 		// Set the cookies up
 		$response = $session->get('/get');
@@ -34,7 +34,7 @@ public function testBasicGET() {
 			'X-Requests-Session' => 'BasicGET',
 			'X-Requests-Request' => 'notset',
 		);
-		$session         = new Requests_Session(httpbin('/'), $session_headers);
+		$session         = new Session(httpbin('/'), $session_headers);
 		$response        = $session->get('/get', array('X-Requests-Request' => 'GET'));
 		$response->throw_for_status(false);
 		$this->assertSame(200, $response->status_code);
@@ -51,7 +51,7 @@ public function testBasicHEAD() {
 			'X-Requests-Session' => 'BasicHEAD',
 			'X-Requests-Request' => 'notset',
 		);
-		$session         = new Requests_Session(httpbin('/'), $session_headers);
+		$session         = new Session(httpbin('/'), $session_headers);
 		$response        = $session->head('/get', array('X-Requests-Request' => 'HEAD'));
 		$response->throw_for_status(false);
 		$this->assertSame(200, $response->status_code);
@@ -62,7 +62,7 @@ public function testBasicDELETE() {
 			'X-Requests-Session' => 'BasicDELETE',
 			'X-Requests-Request' => 'notset',
 		);
-		$session         = new Requests_Session(httpbin('/'), $session_headers);
+		$session         = new Session(httpbin('/'), $session_headers);
 		$response        = $session->delete('/delete', array('X-Requests-Request' => 'DELETE'));
 		$response->throw_for_status(false);
 		$this->assertSame(200, $response->status_code);
@@ -79,7 +79,7 @@ public function testBasicPOST() {
 			'X-Requests-Session' => 'BasicPOST',
 			'X-Requests-Request' => 'notset',
 		);
-		$session         = new Requests_Session(httpbin('/'), $session_headers);
+		$session         = new Session(httpbin('/'), $session_headers);
 		$response        = $session->post('/post', array('X-Requests-Request' => 'POST'), array('postdata' => 'exists'));
 		$response->throw_for_status(false);
 		$this->assertSame(200, $response->status_code);
@@ -96,7 +96,7 @@ public function testBasicPUT() {
 			'X-Requests-Session' => 'BasicPUT',
 			'X-Requests-Request' => 'notset',
 		);
-		$session         = new Requests_Session(httpbin('/'), $session_headers);
+		$session         = new Session(httpbin('/'), $session_headers);
 		$response        = $session->put('/put', array('X-Requests-Request' => 'PUT'), array('postdata' => 'exists'));
 		$response->throw_for_status(false);
 		$this->assertSame(200, $response->status_code);
@@ -113,7 +113,7 @@ public function testBasicPATCH() {
 			'X-Requests-Session' => 'BasicPATCH',
 			'X-Requests-Request' => 'notset',
 		);
-		$session         = new Requests_Session(httpbin('/'), $session_headers);
+		$session         = new Session(httpbin('/'), $session_headers);
 		$response        = $session->patch('/patch', array('X-Requests-Request' => 'PATCH'), array('postdata' => 'exists'));
 		$response->throw_for_status(false);
 		$this->assertSame(200, $response->status_code);
@@ -126,7 +126,7 @@ public function testBasicPATCH() {
 	}
 
 	public function testMultiple() {
-		$session   = new Requests_Session(httpbin('/'), array('X-Requests-Session' => 'Multiple'));
+		$session   = new Session(httpbin('/'), array('X-Requests-Session' => 'Multiple'));
 		$requests  = array(
 			'test1' => array(
 				'url' => httpbin('/get'),
@@ -139,7 +139,7 @@ public function testMultiple() {
 
 		// test1
 		$this->assertNotEmpty($responses['test1']);
-		$this->assertInstanceOf(Requests_Response::class, $responses['test1']);
+		$this->assertInstanceOf(Response::class, $responses['test1']);
 		$this->assertSame(200, $responses['test1']->status_code);
 
 		$result = json_decode($responses['test1']->body, true);
@@ -148,7 +148,7 @@ public function testMultiple() {
 
 		// test2
 		$this->assertNotEmpty($responses['test2']);
-		$this->assertInstanceOf(Requests_Response::class, $responses['test2']);
+		$this->assertInstanceOf(Response::class, $responses['test2']);
 		$this->assertSame(200, $responses['test2']->status_code);
 
 		$result = json_decode($responses['test2']->body, true);
@@ -174,7 +174,7 @@ public function testPropertyUsage() {
 			'foo'        => 'bar',
 		);
 
-		$session = new Requests_Session('http://example.com/', $headers, $data, $options);
+		$session = new Session('http://example.com/', $headers, $data, $options);
 		$this->assertSame('http://example.com/', $session->url);
 		$this->assertSame($headers, $session->headers);
 		$this->assertSame($data, $session->data);
@@ -202,7 +202,7 @@ public function testPropertyUsage() {
 	}
 
 	public function testSharedCookies() {
-		$session = new Requests_Session(httpbin('/'));
+		$session = new Session(httpbin('/'));
 
 		$options  = array(
 			'follow_redirects' => false,
diff --git a/tests/SSLTest.php b/tests/SslTest.php
similarity index 76%
rename from tests/SSLTest.php
rename to tests/SslTest.php
index 7f3c462cd..68d3dbb15 100644
--- a/tests/SSLTest.php
+++ b/tests/SslTest.php
@@ -1,11 +1,11 @@
 <?php
 
-namespace Requests\Tests;
+namespace WpOrg\Requests\Tests;
 
-use Requests\Tests\TestCase;
-use Requests_SSL;
+use WpOrg\Requests\Ssl;
+use WpOrg\Requests\Tests\TestCase;
 
-class SSLTest extends TestCase {
+class SslTest extends TestCase {
 	public static function domainMatchProvider() {
 		return array(
 			array('example.com', 'example.com'),
@@ -40,14 +40,14 @@ public static function domainNoMatchProvider() {
 	 * @dataProvider domainMatchProvider
 	 */
 	public function testMatch($base, $dnsname) {
-		$this->assertTrue(Requests_SSL::match_domain($base, $dnsname));
+		$this->assertTrue(Ssl::match_domain($base, $dnsname));
 	}
 
 	/**
 	 * @dataProvider domainNoMatchProvider
 	 */
 	public function testNoMatch($base, $dnsname) {
-		$this->assertFalse(Requests_SSL::match_domain($base, $dnsname));
+		$this->assertFalse(Ssl::match_domain($base, $dnsname));
 	}
 
 	protected function fakeCertificate($dnsname, $with_san = true) {
@@ -75,7 +75,7 @@ protected function fakeCertificate($dnsname, $with_san = true) {
 	 */
 	public function testMatchViaCertificate($base, $dnsname) {
 		$certificate = $this->fakeCertificate($dnsname);
-		$this->assertTrue(Requests_SSL::verify_certificate($base, $certificate));
+		$this->assertTrue(Ssl::verify_certificate($base, $certificate));
 	}
 
 	/**
@@ -83,17 +83,17 @@ public function testMatchViaCertificate($base, $dnsname) {
 	 */
 	public function testNoMatchViaCertificate($base, $dnsname) {
 		$certificate = $this->fakeCertificate($dnsname);
-		$this->assertFalse(Requests_SSL::verify_certificate($base, $certificate));
+		$this->assertFalse(Ssl::verify_certificate($base, $certificate));
 	}
 
 	public function testCNFallback() {
 		$certificate = $this->fakeCertificate('example.com', false);
-		$this->assertTrue(Requests_SSL::verify_certificate('example.com', $certificate));
+		$this->assertTrue(Ssl::verify_certificate('example.com', $certificate));
 	}
 
 	public function testInvalidCNFallback() {
 		$certificate = $this->fakeCertificate('example.com', false);
-		$this->assertFalse(Requests_SSL::verify_certificate('example.net', $certificate));
+		$this->assertFalse(Ssl::verify_certificate('example.net', $certificate));
 	}
 
 	/**
@@ -107,7 +107,7 @@ public function testInvalidCNFallback() {
 	public function testIgnoreCNWithSAN() {
 		$certificate = $this->fakeCertificate('example.net', 'example.com');
 
-		$this->assertTrue(Requests_SSL::verify_certificate('example.com', $certificate), 'Checking SAN validation');
-		$this->assertFalse(Requests_SSL::verify_certificate('example.net', $certificate), 'Checking CN non-validation');
+		$this->assertTrue(Ssl::verify_certificate('example.com', $certificate), 'Checking SAN validation');
+		$this->assertFalse(Ssl::verify_certificate('example.net', $certificate), 'Checking CN non-validation');
 	}
 }
diff --git a/tests/TestCase.php b/tests/TestCase.php
index da090ca9c..37c317539 100644
--- a/tests/TestCase.php
+++ b/tests/TestCase.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Requests\Tests;
+namespace WpOrg\Requests\Tests;
 
 use Yoast\PHPUnitPolyfills\TestCases\TestCase as Polyfill_TestCase;
 
diff --git a/tests/Transport/BaseTestCase.php b/tests/Transport/BaseTestCase.php
index 1e41d6b81..870fbab7e 100644
--- a/tests/Transport/BaseTestCase.php
+++ b/tests/Transport/BaseTestCase.php
@@ -1,15 +1,16 @@
 <?php
 
-namespace Requests\Tests\Transport;
-
-use Requests;
-use Requests\Tests\Mock\TransportMock;
-use Requests\Tests\TestCase;
-use Requests_Exception;
-use Requests_Exception_HTTP_Unknown;
-use Requests_Hooks;
-use Requests_Response;
+namespace WpOrg\Requests\Tests\Transport;
+
 use stdClass;
+use WpOrg\Requests\Exception;
+use WpOrg\Requests\Exception\Http\StatusUnknown;
+use WpOrg\Requests\Exception\InvalidArgument;
+use WpOrg\Requests\Hooks;
+use WpOrg\Requests\Requests;
+use WpOrg\Requests\Response;
+use WpOrg\Requests\Tests\Mock\TransportMock;
+use WpOrg\Requests\Tests\TestCase;
 
 abstract class BaseTestCase extends TestCase {
 	public function set_up() {
@@ -230,7 +231,7 @@ public function dataIncorrectDataTypeAccepted() {
 	 * @return void
 	 */
 	public function testIncorrectDataTypeExceptionPOST($data) {
-		$this->expectException('Requests_Exception_InvalidArgument');
+		$this->expectException(InvalidArgument::class);
 		$this->expectExceptionMessage('Argument #3 ($data) must be of type array|string');
 
 		$request = Requests::post(httpbin('/post'), array(), $data, $this->getOptions());
@@ -406,7 +407,7 @@ public function testTooManyRedirects() {
 		$options = array(
 			'redirects' => 10, // default, but force just in case
 		);
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('Too many redirects');
 		Requests::get(httpbin('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/redirect/11'), array(), $this->getOptions($options));
 	}
@@ -493,11 +494,11 @@ public function testStatusCodeThrow($code, $success) {
 
 		if (!$success) {
 			if ($code >= 400) {
-				$this->expectException('Requests_Exception_HTTP_' . $code);
+				$this->expectException('\WpOrg\Requests\Exception\Http\Status' . $code);
 				$this->expectExceptionCode($code);
 			}
 			elseif ($code >= 300 && $code < 400) {
-				$this->expectException(Requests_Exception::class);
+				$this->expectException(Exception::class);
 			}
 		}
 
@@ -523,7 +524,7 @@ public function testStatusCodeThrowAllowRedirects($code, $success) {
 
 		if (!$success) {
 			if ($code >= 400 || $code === 304 || $code === 305 || $code === 306) {
-				$this->expectException('Requests_Exception_HTTP_' . $code);
+				$this->expectException('\WpOrg\Requests\Exception\Http\Status' . $code);
 				$this->expectExceptionCode($code);
 			}
 		}
@@ -557,7 +558,7 @@ public function testStatusCodeThrowUnknown() {
 		);
 
 		$request = Requests::get(httpbin('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/status/599'), array(), $options);
-		$this->expectException(Requests_Exception_HTTP_Unknown::class);
+		$this->expectException(StatusUnknown::class);
 		$this->expectExceptionMessage('599 Unknown');
 		$request->throw_for_status(true);
 	}
@@ -604,7 +605,7 @@ public function testStreamToNonWritableFile() {
 			Requests::get(httpbin('/get'), array(), $this->getOptions($options));
 
 			// phpcs:ignore Generic.CodeAnalysis.EmptyStatement.DetectedCatch
-		} catch (Requests_Exception $e) {
+		} catch (Exception $e) {
 			// This "Failed to open stream" exception is expected.
 		}
 
@@ -623,7 +624,7 @@ public function testStreamToInvalidFile() {
 			'filename' => tempnam(sys_get_temp_dir(), 'RLT') . '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/missing/directory', // RequestsLibraryTest
 		);
 
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		// First character (F) can be upper or lowercase depending on PHP version.
 		$this->expectExceptionMessage('ailed to open stream');
 
@@ -635,12 +636,12 @@ public function testNonblocking() {
 			'blocking' => false,
 		);
 		$request = Requests::get(httpbin('/get'), array(), $this->getOptions($options));
-		$empty   = new Requests_Response();
+		$empty   = new Response();
 		$this->assertEquals($empty, $request);
 	}
 
 	public function testBadIP() {
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		Requests::get('http://256.256.256.0/', array(), $this->getOptions());
 	}
 
@@ -663,7 +664,7 @@ public function testExpiredHTTPS() {
 			return;
 		}
 
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		Requests::get('https://testssl-expire.disig.sk/index.en.html', array(), $this->getOptions());
 	}
 
@@ -673,7 +674,7 @@ public function testRevokedHTTPS() {
 			return;
 		}
 
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		Requests::get('https://testssl-revoked.disig.sk/index.en.html', array(), $this->getOptions());
 	}
 
@@ -686,7 +687,7 @@ public function testBadDomain() {
 			return;
 		}
 
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		Requests::head('https://wrong.host.badssl.com/', array(), $this->getOptions());
 	}
 
@@ -737,7 +738,7 @@ public function testTimeout() {
 		$options = array(
 			'timeout' => 1,
 		);
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('timed out');
 		Requests::get(httpbin('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/delay/10'), array(), $this->getOptions($options));
 	}
@@ -755,7 +756,7 @@ public function testMultiple() {
 
 		// test1
 		$this->assertNotEmpty($responses['test1']);
-		$this->assertInstanceOf(Requests_Response::class, $responses['test1']);
+		$this->assertInstanceOf(Response::class, $responses['test1']);
 		$this->assertSame(200, $responses['test1']->status_code);
 
 		$result = json_decode($responses['test1']->body, true);
@@ -764,7 +765,7 @@ public function testMultiple() {
 
 		// test2
 		$this->assertNotEmpty($responses['test2']);
-		$this->assertInstanceOf(Requests_Response::class, $responses['test2']);
+		$this->assertInstanceOf(Response::class, $responses['test2']);
 		$this->assertSame(200, $responses['test2']->status_code);
 
 		$result = json_decode($responses['test2']->body, true);
@@ -811,7 +812,7 @@ public function testMultipleWithFailure() {
 		);
 		$responses = Requests::request_multiple($requests, $this->getOptions());
 		$this->assertSame(200, $responses['success']->status_code);
-		$this->assertInstanceOf(Requests_Exception::class, $responses['timeout']);
+		$this->assertInstanceOf(Exception::class, $responses['timeout']);
 	}
 
 	public function testMultipleUsingCallback() {
@@ -899,12 +900,12 @@ public function testAlternatePort() {
 		try {
 			$request = Requests::get('http://portquiz.net:8080/', array(), $this->getOptions());
 		}
-		catch (Requests_Exception $e) {
+		catch (Exception $e) {
 			// Retry the request as it often times-out.
 			try {
 				$request = Requests::get('http://portquiz.net:8080/', array(), $this->getOptions());
 			}
-			catch (Requests_Exception $e) {
+			catch (Exception $e) {
 				// If it still times out, mark the test as skipped.
 				$this->markTestSkipped(
 					$e->getMessage()
@@ -921,7 +922,7 @@ public function testAlternatePort() {
 	public function testProgressCallback() {
 		$mock = $this->getMockBuilder(stdClass::class)->setMethods(array('progress'))->getMock();
 		$mock->expects($this->atLeastOnce())->method('progress');
-		$hooks = new Requests_Hooks();
+		$hooks = new Hooks();
 		$hooks->register('request.progress', array($mock, 'progress'));
 		$options = array(
 			'hooks' => $hooks,
@@ -942,7 +943,7 @@ public function testAfterRequestCallback() {
 				$this->isType('string'),
 				$this->logicalAnd($this->isType('array'), $this->logicalNot($this->isEmpty()))
 			);
-		$hooks = new Requests_Hooks();
+		$hooks = new Hooks();
 		$hooks->register('curl.after_request', array($mock, 'after_request'));
 		$hooks->register('fsockopen.after_request', array($mock, 'after_request'));
 		$options = array(
diff --git a/tests/Transport/CURLTest.php b/tests/Transport/CurlTest.php
similarity index 88%
rename from tests/Transport/CURLTest.php
rename to tests/Transport/CurlTest.php
index 0125d0c80..bad173afb 100644
--- a/tests/Transport/CURLTest.php
+++ b/tests/Transport/CurlTest.php
@@ -1,29 +1,29 @@
 <?php
 
-namespace Requests\Tests\Transport;
+namespace WpOrg\Requests\Tests\Transport;
 
-use Requests;
-use Requests\Tests\Transport\BaseTestCase;
-use Requests_Exception;
-use Requests_Transport_cURL;
+use WpOrg\Requests\Exception;
+use WpOrg\Requests\Requests;
+use WpOrg\Requests\Tests\Transport\BaseTestCase;
+use WpOrg\Requests\Transport\Curl;
 
 class CurlTest extends BaseTestCase {
-	protected $transport = Requests_Transport_cURL::class;
+	protected $transport = Curl::class;
 
 	public function testBadIP() {
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('t resolve host');
 		parent::testBadIP();
 	}
 
 	public function testExpiredHTTPS() {
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('certificate subject name');
 		parent::testExpiredHTTPS();
 	}
 
 	public function testRevokedHTTPS() {
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('certificate subject name');
 		parent::testRevokedHTTPS();
 	}
@@ -32,7 +32,7 @@ public function testRevokedHTTPS() {
 	 * Test that SSL fails with a bad certificate
 	 */
 	public function testBadDomain() {
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('certificate subject name');
 		parent::testBadDomain();
 	}
diff --git a/tests/Transport/FsockopenTest.php b/tests/Transport/FsockopenTest.php
index ba0f03be2..b130a55ee 100644
--- a/tests/Transport/FsockopenTest.php
+++ b/tests/Transport/FsockopenTest.php
@@ -1,29 +1,29 @@
 <?php
 
-namespace Requests\Tests\Transport;
+namespace WpOrg\Requests\Tests\Transport;
 
-use Requests;
-use Requests\Tests\Transport\BaseTestCase;
-use Requests_Exception;
-use Requests_Hooks;
-use Requests_Transport_fsockopen;
+use WpOrg\Requests\Exception;
+use WpOrg\Requests\Hooks;
+use WpOrg\Requests\Requests;
+use WpOrg\Requests\Tests\Transport\BaseTestCase;
+use WpOrg\Requests\Transport\Fsockopen;
 
 class FsockopenTest extends BaseTestCase {
-	protected $transport = Requests_Transport_fsockopen::class;
+	protected $transport = Fsockopen::class;
 
 	public function testBadIP() {
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		parent::testBadIP();
 	}
 
 	public function testExpiredHTTPS() {
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('SSL certificate did not match the requested domain name');
 		parent::testExpiredHTTPS();
 	}
 
 	public function testRevokedHTTPS() {
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('SSL certificate did not match the requested domain name');
 		parent::testRevokedHTTPS();
 	}
@@ -32,7 +32,7 @@ public function testRevokedHTTPS() {
 	 * Test that SSL fails with a bad certificate
 	 */
 	public function testBadDomain() {
-		$this->expectException(Requests_Exception::class);
+		$this->expectException(Exception::class);
 		$this->expectExceptionMessage('SSL certificate did not match the requested domain name');
 		parent::testBadDomain();
 	}
@@ -41,7 +41,7 @@ public function testBadDomain() {
 	 * Issue #248.
 	 */
 	public function testContentLengthHeader() {
-		$hooks = new Requests_Hooks();
+		$hooks = new Hooks();
 		$hooks->register('fsockopen.after_headers', array($this, 'checkContentLengthHeader'));
 
 		Requests::post(httpbin('/post'), array(), array(), $this->getOptions(array('hooks' => $hooks)));
@@ -67,7 +67,7 @@ public function testHTTPVersionHeader() {
 		// Make sure the locale was changed.
 		$this->assertNotSame($locale, setlocale(LC_NUMERIC, 0), 'Changing the locale failed');
 
-		$hooks = new Requests_Hooks();
+		$hooks = new Hooks();
 		$hooks->register('fsockopen.after_headers', array($this, 'checkHTTPVersionHeader'));
 
 		Requests::post(httpbin('/post'), array(), array(), $this->getOptions(array('hooks' => $hooks)));
diff --git a/tests/Utility/FilteredIteratorTest.php b/tests/Utility/FilteredIteratorTest.php
index 4e37f5281..d9c54319b 100644
--- a/tests/Utility/FilteredIteratorTest.php
+++ b/tests/Utility/FilteredIteratorTest.php
@@ -1,11 +1,11 @@
 <?php
 
-namespace Requests\Tests\Utility;
+namespace WpOrg\Requests\Tests\Utility;
 
 use ArrayIterator;
 use ReflectionClass;
-use Requests\Tests\TestCase;
-use Requests_Utility_FilteredIterator;
+use WpOrg\Requests\Tests\TestCase;
+use WpOrg\Requests\Utility\FilteredIterator;
 
 class FilteredIteratorTest extends TestCase {
 	/**
@@ -13,9 +13,9 @@ class FilteredIteratorTest extends TestCase {
 	 */
 	public function testDeserializeRequestUtilityFilteredIteratorObjects($value) {
 		$serialized = serialize($value);
-		if (get_class($value) === Requests_Utility_FilteredIterator::class) {
+		if (get_class($value) === FilteredIterator::class) {
 			$new_value  = unserialize($serialized);
-			$reflection = new ReflectionClass(Requests_Utility_FilteredIterator::class);
+			$reflection = new ReflectionClass(FilteredIterator::class);
 			$property   = $reflection->getProperty('callback');
 			$property->setAccessible(true);
 			$callback_value = $property->getValue($new_value);
@@ -27,9 +27,9 @@ public function testDeserializeRequestUtilityFilteredIteratorObjects($value) {
 
 	public function dataSerializeDeserializeObjects() {
 		return array(
-			array(new Requests_Utility_FilteredIterator(array(1), 'md5')),
-			array(new Requests_Utility_FilteredIterator(array(1, 2), 'sha1')),
-			array(new Requests_Utility_FilteredIterator(array(1, 2, 3), 'doesnotexist')),
+			array(new FilteredIterator(array(1), 'md5')),
+			array(new FilteredIterator(array(1, 2), 'sha1')),
+			array(new FilteredIterator(array(1, 2, 3), 'doesnotexist')),
 			array(new ArrayIterator(array(1, 2, 3))),
 		);
 	}
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index 3137c883a..ca90eb63a 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -41,8 +41,8 @@ function define_from_env($name, $default = false) {
 	require_once $vendor_dir . '/yoast/phpunit-polyfills/phpunitpolyfills-autoload.php';
 
 	// Load the library autoloader.
-	require_once dirname(__DIR__) . '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/library/Requests.php';
-	Requests::register_autoloader();
+	require_once dirname(__DIR__) . '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/src/Autoload.php';
+	WpOrg\Requests\Autoload::register();
 
 	/*
 	 * Autoloader specifically for the test files.
@@ -52,12 +52,12 @@ function define_from_env($name, $default = false) {
 	spl_autoload_register(
 		function ($class_name) {
 			// Only try & load our own classes.
-			if (stripos($class_name, 'Requests\\Tests\\') !== 0) {
+			if (stripos($class_name, 'WpOrg\\Requests\\Tests\\') !== 0) {
 				return false;
 			}
 
-			// Strip namespace prefix 'Requests\Tests\'.
-			$relative_class = substr($class_name, 15);
+			// Strip namespace prefix 'WpOrg\\Requests\Tests\'.
+			$relative_class = substr($class_name, 21);
 			$file           = realpath(__DIR__ . '/' . strtr($relative_class, '\\', '/') . '.php');
 
 			if (file_exists($file)) {