diff --git a/bundles/best_practices.rst b/bundles/best_practices.rst
index c6e0521db82..64992cae3a9 100644
--- a/bundles/best_practices.rst
+++ b/bundles/best_practices.rst
@@ -421,8 +421,8 @@ The end user can provide values in any configuration file:
         <container xmlns="http://symfony.com/schema/dic/services"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://symfony.com/schema/dic/services
-                https://symfony.com/schema/dic/services/services-1.0.xsd">
-
+                https://symfony.com/schema/dic/services/services-1.0.xsd"
+        >
             <parameters>
                 <parameter key="acme_blog.author.email">fabien@example.com</parameter>
             </parameters>
@@ -432,7 +432,13 @@ The end user can provide values in any configuration file:
     .. code-block:: php
 
         // config/services.php
-        $container->setParameter('acme_blog.author.email', 'fabien@example.com');
+        namespace Symfony\Component\DependencyInjection\Loader\Configurator;
+
+        return static function (ContainerConfigurator $container) {
+            $container->parameters()
+                ->set('acme_blog.author.email', 'fabien@example.com')
+            ;
+        };
 
 Retrieve the configuration parameters in your code from the container::
 
diff --git a/bundles/configuration.rst b/bundles/configuration.rst
index 25254b7efcb..41c34ee7bbc 100644
--- a/bundles/configuration.rst
+++ b/bundles/configuration.rst
@@ -20,19 +20,22 @@ as integration of other related components:
 
     .. code-block:: yaml
 
+        # config/packages/framework.yaml
         framework:
             form: true
 
     .. code-block:: xml
 
+        <!-- config/packages/framework.xml -->
         <?xml version="1.0" encoding="UTF-8" ?>
         <container xmlns="http://symfony.com/schema/dic/services"
+            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:framework="http://symfony.com/schema/dic/symfony"
             xsi:schemaLocation="http://symfony.com/schema/dic/services
                 https://symfony.com/schema/dic/services/services-1.0.xsd
                 http://symfony.com/schema/dic/symfony
-                https://symfony.com/schema/dic/symfony/symfony-1.0.xsd">
-
+                https://symfony.com/schema/dic/symfony/symfony-1.0.xsd"
+        >
             <framework:config>
                 <framework:form/>
             </framework:config>
@@ -40,9 +43,14 @@ as integration of other related components:
 
     .. code-block:: php
 
-        $container->loadFromExtension('framework', [
-            'form' => true,
-        ]);
+        // config/packages/framework.php
+        namespace Symfony\Component\DependencyInjection\Loader\Configurator;
+
+        return static function (ContainerConfigurator $container) {
+            $container->extension('framework', [
+                'form' => true,
+            ]);
+        };
 
 Using the Bundle Extension
 --------------------------
@@ -69,24 +77,28 @@ can add some configuration that looks like this:
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:acme-social="http://example.org/schema/dic/acme_social"
             xsi:schemaLocation="http://symfony.com/schema/dic/services
-                https://symfony.com/schema/dic/services/services-1.0.xsd">
-
+                https://symfony.com/schema/dic/services/services-1.0.xsd"
+        >
             <acme-social:config>
-                <acme-social:twitter client-id="123" client-secret="your_secret"/>
+                <acme-social:twitter client-id="123"
+                    client-secret="your_secret"
+                />
             </acme-social:config>
-
-            <!-- ... -->
         </container>
 
     .. code-block:: php
 
         // config/packages/acme_social.php
-        $container->loadFromExtension('acme_social', [
-            'twitter' => [
-                'client_id'     => 123,
-                'client_secret' => 'your_secret',
-            ],
-        ]);
+        namespace Symfony\Component\DependencyInjection\Loader\Configurator;
+
+        return static function (ContainerConfigurator $container) {
+            $container->extension('acme_social', [
+                'twitter' => [
+                    'client_id'     => 123,
+                    'client_secret' => 'your_secret',
+                ],
+            ]);
+        };
 
 The basic idea is that instead of having the user override individual
 parameters, you let the user configure just a few, specifically created,
@@ -242,8 +254,8 @@ For example, imagine your bundle has the following example config:
     <container xmlns="http://symfony.com/schema/dic/services"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://symfony.com/schema/dic/services
-            https://symfony.com/schema/dic/services/services-1.0.xsd">
-
+            https://symfony.com/schema/dic/services/services-1.0.xsd"
+    >
         <services>
             <service id="acme.social.twitter_client" class="Acme\SocialBundle\TwitterClient">
                 <argument></argument> <!-- will be filled in with client_id dynamically -->
@@ -423,8 +435,8 @@ Assuming the XSD file is called ``hello-1.0.xsd``, the schema location will be
         xsi:schemaLocation="http://symfony.com/schema/dic/services
             https://symfony.com/schema/dic/services/services-1.0.xsd
             http://acme_company.com/schema/dic/hello
-            https://acme_company.com/schema/dic/hello/hello-1.0.xsd">
-
+            https://acme_company.com/schema/dic/hello/hello-1.0.xsd"
+    >
         <acme-hello:config>
             <!-- ... -->
         </acme-hello:config>
diff --git a/bundles/override.rst b/bundles/override.rst
index bf53eb5ce3c..6cf3d37c386 100644
--- a/bundles/override.rst
+++ b/bundles/override.rst
@@ -139,8 +139,8 @@ to a new validation group:
         <constraint-mapping xmlns="http://symfony.com/schema/dic/constraint-mapping"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://symfony.com/schema/dic/constraint-mapping
-                https://symfony.com/schema/dic/constraint-mapping/constraint-mapping-1.0.xsd">
-
+                https://symfony.com/schema/dic/constraint-mapping/constraint-mapping-1.0.xsd"
+        >
             <class name="FOS\UserBundle\Model\User">
                 <property name="plainPassword">
                     <constraint name="NotBlank">
diff --git a/bundles/prepend_extension.rst b/bundles/prepend_extension.rst
index c23f9133ff4..fe551f31083 100644
--- a/bundles/prepend_extension.rst
+++ b/bundles/prepend_extension.rst
@@ -127,29 +127,35 @@ registered and the ``entity_manager_name`` setting for ``acme_hello`` is set to
                 http://example.org/schema/dic/acme_something
                 https://example.org/schema/dic/acme_something/acme_something-1.0.xsd
                 http://example.org/schema/dic/acme_other
-                https://example.org/schema/dic/acme_something/acme_other-1.0.xsd">
-
+                https://example.org/schema/dic/acme_something/acme_other-1.0.xsd"
+        >
             <acme-something:config use-acme-goodbye="false">
                 <!-- ... -->
                 <acme-something:entity-manager-name>non_default</acme-something:entity-manager-name>
             </acme-something:config>
 
-            <acme-other:config use-acme-goodbye="false"/>
+            <acme-other:config use-acme-goodbye="false">
+                <!-- ... -->
+            </acme-other:config>
 
         </container>
 
     .. code-block:: php
 
         // config/packages/acme_something.php
-        $container->loadFromExtension('acme_something', [
-            // ...
-            'use_acme_goodbye' => false,
-            'entity_manager_name' => 'non_default',
-        ]);
-        $container->loadFromExtension('acme_other', [
-            // ...
-            'use_acme_goodbye' => false,
-        ]);
+        namespace Symfony\Component\DependencyInjection\Loader\Configurator;
+
+        return static function (ContainerConfigurator $container) {
+            $container->extension('acme_something', [
+                // ...
+                'use_acme_goodbye' => false,
+                'entity_manager_name' => 'non_default',
+            ]);
+            $container->extension('acme_other', [
+                // ...
+                'use_acme_goodbye' => false,
+            ]);
+        };
 
 More than one Bundle using PrependExtensionInterface
 ----------------------------------------------------
diff --git a/cache.rst b/cache.rst
index 9982c33a7cf..73766284f21 100644
--- a/cache.rst
+++ b/cache.rst
@@ -77,10 +77,11 @@ adapter (template) they use by using the ``app`` and ``system`` key like:
             xsi:schemaLocation="http://symfony.com/schema/dic/services
                 https://symfony.com/schema/dic/services/services-1.0.xsd
                 http://symfony.com/schema/dic/symfony
-                https://symfony.com/schema/dic/symfony/symfony-1.0.xsd">
-
+                https://symfony.com/schema/dic/symfony/symfony-1.0.xsd"
+        >
             <framework:config>
-                <framework:cache app="cache.adapter.filesystem"
+                <framework:cache
+                    app="cache.adapter.filesystem"
                     system="cache.adapter.system"
                 />
             </framework:config>
@@ -89,12 +90,16 @@ adapter (template) they use by using the ``app`` and ``system`` key like:
     .. code-block:: php
 
         // config/packages/cache.php
-        $container->loadFromExtension('framework', [
-            'cache' => [
-                'app' => 'cache.adapter.filesystem',
-                'system' => 'cache.adapter.system',
-            ],
-        ]);
+        namespace Symfony\Component\DependencyInjection\Loader\Configurator;
+
+        return static function (ContainerConfigurator $container) {
+            $container->extension('framework', [
+                'cache' => [
+                    'app' => 'cache.adapter.filesystem',
+                    'system' => 'cache.adapter.system',
+                ],
+            ]);
+        };
 
 The Cache component comes with a series of adapters pre-configured:
 
@@ -140,8 +145,8 @@ will create pools with service IDs that follow the pattern ``cache.[type]``.
             xsi:schemaLocation="http://symfony.com/schema/dic/services
                 https://symfony.com/schema/dic/services/services-1.0.xsd
                 http://symfony.com/schema/dic/symfony
-                https://symfony.com/schema/dic/symfony/symfony-1.0.xsd">
-
+                https://symfony.com/schema/dic/symfony/symfony-1.0.xsd"
+        >
             <framework:config>
                 <!--
                 default_doctrine_provider: Service: cache.doctrine
@@ -164,23 +169,27 @@ will create pools with service IDs that follow the pattern ``cache.[type]``.
     .. code-block:: php
 
         // config/packages/cache.php
-        $container->loadFromExtension('framework', [
-            'cache' => [
-                // Only used with cache.adapter.filesystem
-                'directory' => '%kernel.cache_dir%/pools',
-
-                // Service: cache.doctrine
-                'default_doctrine_provider' => 'app.doctrine_cache',
-                // Service: cache.psr6
-                'default_psr6_provider' => 'app.my_psr6_service',
-                // Service: cache.redis
-                'default_redis_provider' => 'redis://localhost',
-                // Service: cache.memcached
-                'default_memcached_provider' => 'memcached://localhost',
-                // Service: cache.pdo
-                'default_pdo_provider' => 'doctrine.dbal.default_connection',
-            ],
-        ]);
+        namespace Symfony\Component\DependencyInjection\Loader\Configurator;
+
+        return static function (ContainerConfigurator $container) {
+            $container->extension('framework', [
+                'cache' => [
+                    // Only used with cache.adapter.filesystem
+                    'directory' => '%kernel.cache_dir%/pools',
+
+                    // Service: cache.doctrine
+                    'default_doctrine_provider' => 'app.doctrine_cache',
+                    // Service: cache.psr6
+                    'default_psr6_provider' => 'app.my_psr6_service',
+                    // Service: cache.redis
+                    'default_redis_provider' => 'redis://localhost',
+                    // Service: cache.memcached
+                    'default_memcached_provider' => 'memcached://localhost',
+                    // Service: cache.pdo
+                    'default_pdo_provider' => 'doctrine.dbal.default_connection',
+                ],
+            ]);
+        };
 
 Creating Custom (Namespaced) Pools
 ----------------------------------
@@ -233,8 +242,8 @@ You can also create more customized pools:
             xsi:schemaLocation="http://symfony.com/schema/dic/services
                 https://symfony.com/schema/dic/services/services-1.0.xsd
                 http://symfony.com/schema/dic/symfony
-                https://symfony.com/schema/dic/symfony/symfony-1.0.xsd">
-
+                https://symfony.com/schema/dic/symfony/symfony-1.0.xsd"
+        >
             <framework:config>
                 <framework:cache default-memcached-provider="memcached://localhost">
                     <!-- creates a "custom_thing.cache" service
@@ -264,43 +273,47 @@ You can also create more customized pools:
     .. code-block:: php
 
         // config/packages/cache.php
-        $container->loadFromExtension('framework', [
-            'cache' => [
-                'default_memcached_provider' => 'memcached://localhost',
-                'pools' => [
-                    // creates a "custom_thing.cache" service
-                    // autowireable via "CacheInterface $customThingCache"
-                    // uses the "app" cache configuration
-                    'custom_thing.cache' => [
-                        'adapter' => 'cache.app',
-                    ],
+        namespace Symfony\Component\DependencyInjection\Loader\Configurator;
+
+        return static function (ContainerConfigurator $container) {
+            $container->extension('framework', [
+                'cache' => [
+                    'default_memcached_provider' => 'memcached://localhost',
+                    'pools' => [
+                        // creates a "custom_thing.cache" service
+                        // autowireable via "CacheInterface $customThingCache"
+                        // uses the "app" cache configuration
+                        'custom_thing.cache' => [
+                            'adapter' => 'cache.app',
+                        ],
 
-                    // creates a "my_cache_pool" service
-                    // autowireable via "CacheInterface $myCachePool"
-                    'my_cache_pool' => [
-                        'adapter' => 'cache.adapter.filesystem',
-                    ],
+                        // creates a "my_cache_pool" service
+                        // autowireable via "CacheInterface $myCachePool"
+                        'my_cache_pool' => [
+                            'adapter' => 'cache.adapter.filesystem',
+                        ],
 
-                    // uses the default_memcached_provider from above
-                    'acme.cache' => [
-                        'adapter' => 'cache.adapter.memcached',
-                    ],
+                        // uses the default_memcached_provider from above
+                        'acme.cache' => [
+                            'adapter' => 'cache.adapter.memcached',
+                        ],
 
-                    // control adapter's configuration
-                    'foobar.cache' => [
-                        'adapter' => 'cache.adapter.memcached',
-                        'provider' => 'memcached://user:password@example.com',
-                    ],
+                        // control adapter's configuration
+                        'foobar.cache' => [
+                            'adapter' => 'cache.adapter.memcached',
+                            'provider' => 'memcached://user:password@example.com',
+                        ],
 
-                    // uses the "foobar.cache" pool as its backend but controls
-                    // the lifetime and (like all pools) has a separate cache namespace
-                    'short_cache' => [
-                        'adapter' => 'foobar.cache',
-                        'default_lifetime' => 60,
+                        // uses the "foobar.cache" pool as its backend but controls
+                        // the lifetime and (like all pools) has a separate cache namespace
+                        'short_cache' => [
+                            'adapter' => 'foobar.cache',
+                            'default_lifetime' => 60,
+                        ],
                     ],
                 ],
-            ],
-        ]);
+            ]);
+        };
 
 Each pool manages a set of independent cache keys: keys from different pools
 *never* collide, even if they share the same backend. This is achieved by prefixing
@@ -342,6 +355,8 @@ with either :class:`Symfony\\Contracts\\Cache\\CacheInterface` or
 
             # config/services.yaml
             services:
+                # ...
+
                 app.cache.adapter.redis:
                     parent: 'cache.adapter.redis'
                     tags:
@@ -354,9 +369,11 @@ with either :class:`Symfony\\Contracts\\Cache\\CacheInterface` or
             <container xmlns="http://symfony.com/schema/dic/services"
                 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                 xsi:schemaLocation="http://symfony.com/schema/dic/services
-                    https://symfony.com/schema/dic/services/services-1.0.xsd">
-
+                    https://symfony.com/schema/dic/services/services-1.0.xsd"
+            >
                 <services>
+                    <!-- ... -->
+
                     <service id="app.cache.adapter.redis" parent="cache.adapter.redis">
                         <tag name="cache.pool" namespace="my_custom_namespace"/>
                     </service>
@@ -368,12 +385,14 @@ with either :class:`Symfony\\Contracts\\Cache\\CacheInterface` or
             // config/services.php
             namespace Symfony\Component\DependencyInjection\Loader\Configurator;
 
-            return function(ContainerConfigurator $configurator) {
-                $services = $configurator->services();
+            return function(ContainerConfigurator $container) {
+                $container->services()
+                    // ...
 
-                $services->set('app.cache.adapter.redis')
-                    ->parent('cache.adapter.redis')
-                    ->tag('cache.pool', ['namespace' => 'my_custom_namespace']);
+                    ->set('app.cache.adapter.redis')
+                        ->parent('cache.adapter.redis')
+                        ->tag('cache.pool', ['namespace' => 'my_custom_namespace'])
+                ;
             };
 
 Custom Provider Options
@@ -415,11 +434,14 @@ and use that when configuring the pool.
             xsi:schemaLocation="http://symfony.com/schema/dic/services
                 https://symfony.com/schema/dic/services/services-1.0.xsd
                 http://symfony.com/schema/dic/symfony
-                https://symfony.com/schema/dic/symfony/symfony-1.0.xsd">
-
+                https://symfony.com/schema/dic/symfony/symfony-1.0.xsd"
+        >
             <framework:config>
                 <framework:cache>
-                    <framework:pool name="cache.my_redis" adapter="cache.adapter.redis" provider="app.my_custom_redis_provider"/>
+                    <framework:pool name="cache.my_redis"
+                        adapter="cache.adapter.redis"
+                        provider="app.my_custom_redis_provider"
+                    />
                 </framework:cache>
             </framework:config>
 
@@ -438,27 +460,34 @@ and use that when configuring the pool.
     .. code-block:: php
 
         // config/packages/cache.php
+        namespace Symfony\Component\DependencyInjection\Loader\Configurator;
+
         use Symfony\Component\Cache\Adapter\RedisAdapter;
 
-        $container->loadFromExtension('framework', [
-            'cache' => [
-                'pools' => [
-                    'cache.my_redis' => [
-                        'adapter' => 'cache.adapter.redis',
-                        'provider' => 'app.my_custom_redis_provider',
+        return static function (ContainerConfigurator $container) {
+            $container->extension('framework', [
+                'cache' => [
+                    'pools' => [
+                        'cache.my_redis' => [
+                            'adapter' => 'cache.adapter.redis',
+                            'provider' => 'app.my_custom_redis_provider',
+                        ],
                     ],
                 ],
-            ],
-        ]);
-
-        $container->register('app.my_custom_redis_provider', \Redis::class)
-            ->setFactory([RedisAdapter::class, 'createConnection'])
-            ->addArgument('redis://localhost')
-            ->addArgument([
-                'retry_interval' => 2,
-                'timeout' => 10
-            ])
-        ;
+            ]);
+
+            $container->services()
+                ->set('app.my_custom_redis_provider', \Redis::class)
+                    ->factory([RedisAdapter::class, 'createConnection'])
+                    ->args([
+                        'redis://localhost',
+                        [
+                            'retry_interval' => 2,
+                            'timeout' => 10,
+                        ]
+                    ])
+            ;
+        };
 
 Creating a Cache Chain
 ----------------------
@@ -506,11 +535,14 @@ Symfony stores the item automatically in all the missing pools.
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:framework="http://symfony.com/schema/dic/symfony"
             xsi:schemaLocation="http://symfony.com/schema/dic/services
-                https://symfony.com/schema/dic/services/services-1.0.xsd">
-
+                https://symfony.com/schema/dic/services/services-1.0.xsd
+                http://symfony.com/schema/dic/symfony
+                https://symfony.com/schema/dic/symfony/symfony-1.0.xsd"
+        >
             <framework:config>
                 <framework:cache>
-                    <framework:pool name="my_cache_pool" default-lifetime="31536000">
+                    <framework:pool name="my_cache_pool"
+                        default-lifetime="31536000"> <!-- One year -->
                         <framework:adapter name="cache.adapter.array"/>
                         <framework:adapter name="cache.adapter.apcu"/>
                         <framework:adapter name="cache.adapter.redis" provider="redis://user:password@example.com"/>
@@ -522,20 +554,24 @@ Symfony stores the item automatically in all the missing pools.
     .. code-block:: php
 
         // config/packages/cache.php
-        $container->loadFromExtension('framework', [
-            'cache' => [
-                'pools' => [
-                    'my_cache_pool' => [
-                        'default_lifetime' => 31536000, // One year
-                        'adapters' => [
-                            'cache.adapter.array',
-                            'cache.adapter.apcu',
-                            ['name' => 'cache.adapter.redis', 'provider' => 'redis://user:password@example.com'],
+        namespace Symfony\Component\DependencyInjection\Loader\Configurator;
+
+        return static function (ContainerConfigurator $container) {
+            $container->extension('framework', [
+                'cache' => [
+                    'pools' => [
+                        'my_cache_pool' => [
+                            'default_lifetime' => 31536000, // One year
+                            'adapters' => [
+                                'cache.adapter.array',
+                                'cache.adapter.apcu',
+                                ['name' => 'cache.adapter.redis', 'provider' => 'redis://user:password@example.com'],
+                            ],
                         ],
                     ],
                 ],
-            ],
-        ]);
+            ]);
+        };
 
 Using Cache Tags
 ----------------
@@ -602,11 +638,14 @@ to enable this feature. This could be added by using the following configuration
             xsi:schemaLocation="http://symfony.com/schema/dic/services
                 https://symfony.com/schema/dic/services/services-1.0.xsd
                 http://symfony.com/schema/dic/symfony
-                https://symfony.com/schema/dic/symfony/symfony-1.0.xsd">
-
+                https://symfony.com/schema/dic/symfony/symfony-1.0.xsd"
+        >
             <framework:config>
                 <framework:cache>
-                  <framework:pool name="my_cache_pool" adapter="cache.adapter.redis" tags="true"/>
+                    <framework:pool name="my_cache_pool"
+                        adapter="cache.adapter.redis"
+                        tags="true"
+                    />
                 </framework:cache>
             </framework:config>
         </container>
@@ -614,16 +653,20 @@ to enable this feature. This could be added by using the following configuration
     .. code-block:: php
 
         // config/packages/cache.php
-        $container->loadFromExtension('framework', [
-            'cache' => [
-                'pools' => [
-                    'my_cache_pool' => [
-                        'adapter' => 'cache.adapter.redis',
-                        'tags' => true,
+        namespace Symfony\Component\DependencyInjection\Loader\Configurator;
+
+        return static function (ContainerConfigurator $container) {
+            $container->extension('framework', [
+                'cache' => [
+                    'pools' => [
+                        'my_cache_pool' => [
+                            'adapter' => 'cache.adapter.redis',
+                            'tags' => true,
+                        ],
                     ],
                 ],
-            ],
-        ]);
+            ]);
+        };
 
 Tags are stored in the same pool by default. This is good in most scenarios. But
 sometimes it might be better to store the tags in a different pool. That could be
@@ -651,12 +694,17 @@ achieved by specifying the adapter.
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:framework="http://symfony.com/schema/dic/symfony"
             xsi:schemaLocation="http://symfony.com/schema/dic/services
-                https://symfony.com/schema/dic/services/services-1.0.xsd">
-
+                https://symfony.com/schema/dic/services/services-1.0.xsd
+                http://symfony.com/schema/dic/symfony
+                https://symfony.com/schema/dic/symfony/symfony-1.0.xsd"
+        >
             <framework:config>
                 <framework:cache>
-                  <framework:pool name="my_cache_pool" adapter="cache.adapter.redis" tags="tag_pool"/>
-                  <framework:pool name="tag_pool" adapter="cache.adapter.apcu"/>
+                    <framework:pool name="my_cache_pool"
+                        adapter="cache.adapter.redis"
+                        tags="tag_pool"
+                    />
+                    <framework:pool name="tag_pool" adapter="cache.adapter.apcu"/>
                 </framework:cache>
             </framework:config>
         </container>
@@ -664,19 +712,23 @@ achieved by specifying the adapter.
     .. code-block:: php
 
         // config/packages/cache.php
-        $container->loadFromExtension('framework', [
-            'cache' => [
-                'pools' => [
-                    'my_cache_pool' => [
-                        'adapter' => 'cache.adapter.redis',
-                        'tags' => 'tag_pool',
-                    ],
-                    'tag_pool' => [
-                        'adapter' => 'cache.adapter.apcu',
+        namespace Symfony\Component\DependencyInjection\Loader\Configurator;
+
+        return static function (ContainerConfigurator $container) {
+            $container->extension('framework', [
+                'cache' => [
+                    'pools' => [
+                        'my_cache_pool' => [
+                            'adapter' => 'cache.adapter.redis',
+                            'tags' => 'tag_pool',
+                        ],
+                        'tag_pool' => [
+                            'adapter' => 'cache.adapter.apcu',
+                        ],
                     ],
                 ],
-            ],
-        ]);
+            ]);
+        };
 
 .. note::
 
diff --git a/components/dependency_injection.rst b/components/dependency_injection.rst
index 486f89e599d..fab46ff3d26 100644
--- a/components/dependency_injection.rst
+++ b/components/dependency_injection.rst
@@ -259,15 +259,16 @@ config files:
             newsletter_manager:
                 class:     NewsletterManager
                 calls:
-                    - setMailer: ['@mailer']
+                    - [setMailer, ['@mailer']]
 
     .. code-block:: xml
 
         <?xml version="1.0" encoding="UTF-8" ?>
         <container xmlns="http://symfony.com/schema/dic/services"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-            xsi:schemaLocation="http://symfony.com/schema/dic/services https://symfony.com/schema/dic/services/services-1.0.xsd">
-
+            xsi:schemaLocation="http://symfony.com/schema/dic/services
+                https://symfony.com/schema/dic/services/services-1.0.xsd"
+        >
             <parameters>
                 <!-- ... -->
                 <parameter key="mailer.transport">sendmail</parameter>
@@ -290,24 +291,21 @@ config files:
 
         namespace Symfony\Component\DependencyInjection\Loader\Configurator;
 
-        return function(ContainerConfigurator $configurator) {
-            $configurator->parameters()
+        return static function (ContainerConfigurator $container) {
+            $container->parameters()
                 // ...
                 ->set('mailer.transport', 'sendmail')
             ;
 
-            $services = $configurator->services();
-
-            $services->set('mailer', 'Mailer')
-                ->args(['%mailer.transport%'])
-            ;
+            $container->services()
+                ->set('mailer', 'Mailer')
+                    ->args(['%mailer.transport%'])
 
-            $services->set('newsletter_manager', 'NewsletterManager')
-                ->call('setMailer', [ref('mailer')])
+                ->set('newsletter_manager', 'NewsletterManager')
+                    ->call('setMailer', [ref('mailer')])
             ;
         };
 
-
 Learn More
 ----------
 
diff --git a/components/dependency_injection/_imports-parameters-note.rst.inc b/components/dependency_injection/_imports-parameters-note.rst.inc
index 92868df1985..50c6b736353 100644
--- a/components/dependency_injection/_imports-parameters-note.rst.inc
+++ b/components/dependency_injection/_imports-parameters-note.rst.inc
@@ -19,8 +19,8 @@
             <container xmlns="http://symfony.com/schema/dic/services"
                 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                 xsi:schemaLocation="http://symfony.com/schema/dic/services
-                    https://symfony.com/schema/dic/services/services-1.0.xsd">
-
+                    https://symfony.com/schema/dic/services/services-1.0.xsd"
+            >
                 <imports>
                     <import resource="%kernel.project_dir%/somefile.yaml"/>
                 </imports>
@@ -29,4 +29,8 @@
         .. code-block:: php
 
             // config/services.php
-            $loader->import('%kernel.project_dir%/somefile.yaml');
+            namespace Symfony\Component\DependencyInjection\Loader\Configurator;
+
+            return static function (ContainerConfigurator $container) {
+                $container->import('%kernel.project_dir%/somefile.yaml');
+            };
diff --git a/components/dependency_injection/compilation.rst b/components/dependency_injection/compilation.rst
index acf754c0f5d..3f5812529b2 100644
--- a/components/dependency_injection/compilation.rst
+++ b/components/dependency_injection/compilation.rst
@@ -200,13 +200,16 @@ The XML version of the config would then look like this:
     <?xml version="1.0" encoding="UTF-8" ?>
     <container xmlns="http://symfony.com/schema/dic/services"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-        xmlns:acme_demo="http://www.example.com/symfony/schema/"
-        xsi:schemaLocation="http://www.example.com/symfony/schema/ https://www.example.com/symfony/schema/hello-1.0.xsd">
-
-        <acme_demo:config>
+        xmlns:acme-demo="http://www.example.com/schema/dic/acme_demo"
+        xsi:schemaLocation="http://symfony.com/schema/dic/services
+            https://symfony.com/schema/dic/services/services-1.0.xsd
+            http://www.example.com/schema/dic/acme_demo
+            https://www.example.com/schema/dic/acme_demo/acme_demo-1.0.xsd"
+    >
+        <acme-demo:config>
             <acme_demo:foo>fooValue</acme_demo:foo>
             <acme_demo:bar>barValue</acme_demo:bar>
-        </acme_demo:config>
+        </acme-demo:config>
     </container>
 
 .. note::
diff --git a/components/http_foundation/session_configuration.rst b/components/http_foundation/session_configuration.rst
index 41aacae0e46..36ca212b006 100644
--- a/components/http_foundation/session_configuration.rst
+++ b/components/http_foundation/session_configuration.rst
@@ -187,21 +187,26 @@ configuration:
             xmlns:framework="http://symfony.com/schema/dic/symfony"
             xsi:schemaLocation="http://symfony.com/schema/dic/services
                 https://symfony.com/schema/dic/services/services-1.0.xsd
-                http://symfony.com/schema/dic/symfony https://symfony.com/schema/dic/symfony/symfony-1.0.xsd">
-
+                http://symfony.com/schema/dic/symfony
+                https://symfony.com/schema/dic/symfony/symfony-1.0.xsd"
+        >
             <framework:config>
-                <framework:session gc_probability="null"/>
+                <framework:session gc-probability="null"/>
             </framework:config>
         </container>
 
     .. code-block:: php
 
         // config/packages/framework.php
-        $container->loadFromExtension('framework', [
-            'session' => [
-                'gc_probability' => null,
-            ],
-        ]);
+        namespace Symfony\Component\DependencyInjection\Loader\Configurator;
+
+        return static function (ContainerConfigurator $container) {
+            $container->extension('framework', [
+                'session' => [
+                    'gc_probability' => null,
+                ],
+            ]);
+        };
 
 You can configure these settings by passing ``gc_probability``, ``gc_divisor``
 and ``gc_maxlifetime`` in an array to the constructor of
diff --git a/components/serializer.rst b/components/serializer.rst
index c26cd480134..81707bc5a05 100644
--- a/components/serializer.rst
+++ b/components/serializer.rst
@@ -816,6 +816,8 @@ faster alternative to the
 
         # config/services.yaml
         services:
+            # ...
+
             get_set_method_normalizer:
                 class: Symfony\Component\Serializer\Normalizer\GetSetMethodNormalizer
                 tags: [serializer.normalizer]
@@ -827,9 +829,11 @@ faster alternative to the
         <container xmlns="http://symfony.com/schema/dic/services"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://symfony.com/schema/dic/services
-                https://symfony.com/schema/dic/services/services-1.0.xsd">
-
+                https://symfony.com/schema/dic/services/services-1.0.xsd"
+        >
             <services>
+                <!-- ... -->
+
                 <service id="get_set_method_normalizer" class="Symfony\Component\Serializer\Normalizer\GetSetMethodNormalizer">
                     <tag name="serializer.normalizer"/>
                 </service>
@@ -843,11 +847,11 @@ faster alternative to the
 
         use Symfony\Component\Serializer\Normalizer\GetSetMethodNormalizer;
 
-        return function(ContainerConfigurator $configurator) {
-            $services = $configurator->services();
-
-            $services->set('get_set_method_normalizer', GetSetMethodNormalizer::class)
-                ->tag('serializer.normalizer')
+        return static function (ContainerConfigurator $container) {
+            $container->services()
+                // ...
+                ->set('get_set_method_normalizer', GetSetMethodNormalizer::class)
+                    ->tag('serializer.normalizer')
             ;
         };
 
diff --git a/components/var_dumper.rst b/components/var_dumper.rst
index a607ddeb59b..1202791b97c 100644
--- a/components/var_dumper.rst
+++ b/components/var_dumper.rst
@@ -131,22 +131,27 @@ the :ref:`dump_destination option <configuration-debug-dump_destination>` of the
 
         <!-- config/packages/debug.xml -->
         <?xml version="1.0" encoding="UTF-8" ?>
-        <container xmlns="http://symfony.com/schema/dic/debug"
+        <container xmlns="http://symfony.com/schema/dic/services"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:debug="http://symfony.com/schema/dic/debug"
             xsi:schemaLocation="http://symfony.com/schema/dic/services
                 https://symfony.com/schema/dic/services/services-1.0.xsd
-                http://symfony.com/schema/dic/debug https://symfony.com/schema/dic/debug/debug-1.0.xsd">
-
+                http://symfony.com/schema/dic/debug
+                https://symfony.com/schema/dic/debug/debug-1.0.xsd"
+        >
             <debug:config dump-destination="tcp://%env(VAR_DUMPER_SERVER)%"/>
         </container>
 
     .. code-block:: php
 
         // config/packages/debug.php
-        $container->loadFromExtension('debug', [
-           'dump_destination' => 'tcp://%env(VAR_DUMPER_SERVER)%',
-        ]);
+        namespace Symfony\Component\DependencyInjection\Loader\Configurator;
+
+        return static function (ContainerConfigurator $container) {
+            $container->extension('debug', [
+                'dump_destination' => 'tcp://%env(VAR_DUMPER_SERVER)%',
+            ]);
+        };
 
 Outside a Symfony application, use the :class:`Symfony\\Component\\VarDumper\\Dumper\\ServerDumper` class::