diff --git a/core/lib/Drupal/Component/Plugin/Context/Context.php b/core/lib/Drupal/Component/Plugin/Context/Context.php
new file mode 100644
index 0000000..ce8ccf4
--- /dev/null
+++ b/core/lib/Drupal/Component/Plugin/Context/Context.php
@@ -0,0 +1,55 @@
+<?php
+
+/**
+ * @file
+ * Contains Drupal\Component\Plugin\Context\Context.
+ */
+
+namespace Drupal\Component\Plugin\Context;
+
+use Drupal\Component\Plugin\Exception\ContextException;
+
+/**
+ * A generic context wrapper class.
+ */
+class Context {
+
+  /**
+   * The context.
+   *
+   * @var mixed
+   */
+  protected $context;
+
+  /**
+   * The class name or an array definition to which a context must conform.
+   *
+   * @var mixed
+   *  A string or array.
+   */
+  protected $contextDefinition;
+
+  public function __construct($contextDefinition) {
+    $this->contextDefinition = $contextDefinition;
+  }
+
+  public function setContext($context) {
+    $context = $this->validate($context);
+    $this->context = $context;
+  }
+
+  public function getContext() {
+    return $this->context;
+  }
+
+  public function validate($context) {
+    if (is_string($this->contextDefinition)) {
+      if ($context instanceof $this->contextDefinition) {
+        return $context;
+      }
+      throw new ContextException("The context passed was not an instance of $this->contextDefinition.");
+    }
+    throw new ContextException("An error was encountered while trying to validate the context.");
+  }
+
+}
\ No newline at end of file
diff --git a/core/lib/Drupal/Component/Plugin/ContextualPluginBase.php b/core/lib/Drupal/Component/Plugin/ContextualPluginBase.php
new file mode 100644
index 0000000..a48d3e6
--- /dev/null
+++ b/core/lib/Drupal/Component/Plugin/ContextualPluginBase.php
@@ -0,0 +1,97 @@
+<?php
+/**
+ * @file
+ * Definition of Drupal\Component\Plugin\ContextualPluginBase
+ */
+
+namespace Drupal\Component\Plugin;
+
+use Drupal\Component\Plugin\Exception\PluginException;
+use Drupal\Component\Plugin\Context\Context;
+
+/**
+ * Base class for plugins that use context.
+ */
+abstract class ContextualPluginBase extends PluginBase {
+
+  /**
+   * Returns the context definitions of the plugin.
+   *
+   * @return mixed
+   *   The context definitions if set, otherwise NULL.
+   */
+  public function getContextDefinitions() {
+    $definition = $this->getDefinition();
+    return !empty($definition['context']) ? $definition['context'] : NULL;
+  }
+
+  /**
+   * Returns the a specific context class definition of the plugin.
+   *
+   * @return string
+   *   The name of a class to which the set context must conform.
+   */
+  public function getContextDefinition($key) {
+    $definition = $this->getDefinition();
+    if (empty($definition['context'][$key])) {
+      throw new PluginException("The $key context is not a valid context.");
+    }
+    return $definition['context'][$key];
+  }
+
+  /**
+   * Returns the set values for all defined contexts.
+   *
+   * @return array
+   *   Returns the array of all set contexts.
+   */
+  public function getContexts() {
+    if (empty($this->configuration['context'])) {
+      throw new PluginException("There are no set contexts.");
+    }
+    return $this->configuration['context'];
+  }
+
+  /**
+   * Returns the set value for a defined context.
+   *
+   * @return object
+   *   Returns instantiated object of a context.
+   */
+  public function getContext($key) {
+    return $this->getContextWrapper($key)->getContext();
+  }
+
+  /**
+   * Returns the set context wrapper for a defined context.
+   *
+   * @return object
+   *   Returns a context wrapper object.
+   */
+  public function getContextWrapper($key) {
+    $definition = $this->getDefinition();
+    if (empty($definition['context'][$key])) {
+      throw new PluginException("The $key context is not a valid context.");
+    }
+    if (empty($this->configuration['context'][$key])) {
+      throw new PluginException("The $key context is not yet set.");
+    }
+
+    return $this->configuration['context'][$key];
+  }
+
+  /**
+   * Sets a defined context to the passed value.
+   *
+   * @return $this
+   *   Returns the plugin instance.
+   */
+  public function setContext($key, $value) {
+    $class = $this->getContextDefinition($key);
+    $this->configuration['context'][$key] = new Context($class);
+    $this->configuration['context'][$key]->setContext($value);
+
+    return $this;
+  }
+
+}
diff --git a/core/lib/Drupal/Component/Plugin/Exception/ContextException.php b/core/lib/Drupal/Component/Plugin/Exception/ContextException.php
new file mode 100644
index 0000000..fbb1c2d
--- /dev/null
+++ b/core/lib/Drupal/Component/Plugin/Exception/ContextException.php
@@ -0,0 +1,15 @@
+<?php
+/**
+ * @file
+ * Definition of Drupal\Component\Plugin\Exception\ContextException.
+ */
+
+namespace Drupal\Component\Plugin\Exception;
+
+use Exception;
+
+/**
+ * Generic Plugin exception class to be thrown when no more specific class
+ * is applicable.
+ */
+class ContextException extends Exception implements ExceptionInterface { }
diff --git a/core/lib/Drupal/Core/Plugin/Context/Context.php b/core/lib/Drupal/Core/Plugin/Context/Context.php
new file mode 100644
index 0000000..cf919d5
--- /dev/null
+++ b/core/lib/Drupal/Core/Plugin/Context/Context.php
@@ -0,0 +1,49 @@
+<?php
+
+/**
+ * @file
+ * Contains Drupal\Core\Plugin\Context\Context.
+ */
+
+namespace Drupal\Core\Plugin\Context;
+
+use Drupal\Component\Plugin\Context\Context as ComponentContext;
+use Drupal\Component\Plugin\Exception\ContextException;
+use Drupal\Core\TypedData\TypedDataManager;
+
+/**
+ * A Drupal specific context wrapper class.
+ *
+ * The validate method is specifically overridden in order to support typed
+ * data definitions instead of just class names in the contextual definitions
+ * of plugins that extend ContextualPluginBase.
+ */
+class Context extends ComponentContext {
+
+  /**
+   * Override for Drupal\Component\Plugin\Context\Context::validate().
+   */
+  public function validate($context) {
+    // Check to make sure we have a class name, and that the passed context is
+    // an instance of that class name.
+    if (is_string($this->contextDefinition)) {
+      if ($context instanceof $this->contextDefinition) {
+        return $context;
+      }
+      throw new ContextException("The context passed was not an instance of $this->contextDefinition.");
+    }
+    // Check to see if we have a typed data definition instead of a class name.
+    if (is_array($this->contextDefinition)) {
+      $typed_data_manager = new TypedDataManager();
+      $typed_data = $typed_data_manager->create($this->contextDefinition, $context);
+      // If we do have a typed data definition, validate it and return the
+      // typed data instance instead.
+      if ($typed_data->validate()) {
+        return $typed_data;
+      }
+      throw new ContextException("The context passed could not be validated through typed data.");
+    }
+    throw new ContextException("An error was encountered while trying to validate the context.");
+  }
+
+}
\ No newline at end of file
diff --git a/core/lib/Drupal/Core/Plugin/ContextualPluginBase.php b/core/lib/Drupal/Core/Plugin/ContextualPluginBase.php
new file mode 100644
index 0000000..ea47c33
--- /dev/null
+++ b/core/lib/Drupal/Core/Plugin/ContextualPluginBase.php
@@ -0,0 +1,32 @@
+<?php
+/**
+ * @file
+ * Definition of Drupal\Core\Plugin\ContextualPluginBase
+ */
+
+namespace Drupal\Core\Plugin;
+
+use Drupal\Component\Plugin\ContextualPluginBase as PluginBase;
+use Drupal\Core\Plugin\Context\Context;
+
+/**
+ * Drupal specific class for plugins that use context.
+ *
+ * This class specifically overrides setContext to use the core version of
+ * the Context wrapper class. This code is exactly the same as what is in
+ * Component ContextualPluginBase but it is using a different Context class.
+ */
+abstract class ContextualPluginBase extends PluginBase {
+
+  /**
+   * Override of Drupal\Component\Plugin\ContextualPluginBase::setContext().
+   */
+  public function setContext($key, $value) {
+    $class = $this->getContextDefinition($key);
+    $this->configuration['context'][$key] = new Context($class);
+    $this->configuration['context'][$key]->setContext($value);
+
+    return $this;
+  }
+
+}
diff --git a/core/lib/Drupal/Core/TypedData/Type/Boolean.php b/core/lib/Drupal/Core/TypedData/Type/Boolean.php
index c8797ef..b0f5027 100644
--- a/core/lib/Drupal/Core/TypedData/Type/Boolean.php
+++ b/core/lib/Drupal/Core/TypedData/Type/Boolean.php
@@ -35,6 +35,6 @@ public function setValue($value) {
    * Implements TypedDataInterface::validate().
    */
   public function validate() {
-    // TODO: Implement validate() method.
+    return is_bool($this->value);
   }
 }
diff --git a/core/lib/Drupal/Core/TypedData/Type/Email.php b/core/lib/Drupal/Core/TypedData/Type/Email.php
index e9a9c5a..8a1acb6 100644
--- a/core/lib/Drupal/Core/TypedData/Type/Email.php
+++ b/core/lib/Drupal/Core/TypedData/Type/Email.php
@@ -18,7 +18,7 @@ class Email extends String {
    * Implements \Drupal\Core\TypedData\TypedDataInterface::validate().
    */
   public function validate() {
-    // @todo Implement validate() method.
+    return filter_var($this->value, FILTER_VALIDATE_EMAIL) ? TRUE : FALSE;
   }
 
 }
diff --git a/core/lib/Drupal/Core/TypedData/Type/Float.php b/core/lib/Drupal/Core/TypedData/Type/Float.php
index 3e8369b..34730fb 100644
--- a/core/lib/Drupal/Core/TypedData/Type/Float.php
+++ b/core/lib/Drupal/Core/TypedData/Type/Float.php
@@ -35,6 +35,6 @@ public function setValue($value) {
    * Implements TypedDataInterface::validate().
    */
   public function validate() {
-    // TODO: Implement validate() method.
+    return filter_var($this->value, FILTER_VALIDATE_FLOAT) ? TRUE : FALSE;
   }
 }
diff --git a/core/lib/Drupal/Core/TypedData/Type/Integer.php b/core/lib/Drupal/Core/TypedData/Type/Integer.php
index 4303511..43f7886 100644
--- a/core/lib/Drupal/Core/TypedData/Type/Integer.php
+++ b/core/lib/Drupal/Core/TypedData/Type/Integer.php
@@ -35,6 +35,6 @@ public function setValue($value) {
    * Implements TypedDataInterface::validate().
    */
   public function validate() {
-    // TODO: Implement validate() method.
+    return filter_var($this->value, FILTER_VALIDATE_INT) ? TRUE : FALSE;
   }
 }
diff --git a/core/lib/Drupal/Core/TypedData/Type/String.php b/core/lib/Drupal/Core/TypedData/Type/String.php
index 9248239..ed1d5a3 100644
--- a/core/lib/Drupal/Core/TypedData/Type/String.php
+++ b/core/lib/Drupal/Core/TypedData/Type/String.php
@@ -35,6 +35,6 @@ public function setValue($value) {
    * Implements TypedDataInterface::validate().
    */
   public function validate() {
-    // TODO: Implement validate() method.
+    return is_string($this->value);
   }
 }
diff --git a/core/lib/Drupal/Core/TypedData/Type/Uri.php b/core/lib/Drupal/Core/TypedData/Type/Uri.php
index 52b9c3f..ee3dc9f 100644
--- a/core/lib/Drupal/Core/TypedData/Type/Uri.php
+++ b/core/lib/Drupal/Core/TypedData/Type/Uri.php
@@ -34,6 +34,6 @@ public function setValue($value) {
    * Implements TypedDataInterface::validate().
    */
   public function validate() {
-    // TODO: Implement validate() method.
+    return filter_var($this->value, FILTER_VALIDATE_URL) ? TRUE : FALSE;
   }
 }
diff --git a/core/modules/system/lib/Drupal/system/Tests/Plugin/ContextPluginTest.php b/core/modules/system/lib/Drupal/system/Tests/Plugin/ContextPluginTest.php
new file mode 100644
index 0000000..470b795
--- /dev/null
+++ b/core/modules/system/lib/Drupal/system/Tests/Plugin/ContextPluginTest.php
@@ -0,0 +1,119 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\system\Tests\Plugin\ContextPluginTest.
+ */
+
+namespace Drupal\system\Tests\Plugin;
+
+use Drupal\simpletest\DrupalUnitTestBase;
+use Drupal\plugin_test\Plugin\MockBlockManager;
+use Drupal\plugin_test\MockNode;
+use Drupal\plugin_test\MockUser;
+use Drupal\Component\Plugin\Exception\PluginException;
+use Drupal\Component\Plugin\Exception\ContextException;
+
+/**
+ * Tests that derivative plugins are correctly discovered.
+ */
+class ContextPluginTest extends DrupalUnitTestBase {
+
+  public static $modules = array('system');
+
+  public static function getInfo() {
+    return array(
+      'name' => 'Contextual Plugins',
+      'description' => 'Tests that contexts are properly set and working within plugins.',
+      'group' => 'Plugin API',
+    );
+  }
+
+  /**
+   * Tests getDefinitions() and getDefinition() with a derivativeDecorator.
+   */
+  function testContext() {
+    $name = $this->randomName();
+    $manager = new MockBlockManager();
+    $plugin = $manager->createInstance('user_name');
+    // Create a node, add it as context, catch the exception.
+    $node = new MockNode(array('title' => $name));
+
+    // Try to get a valid context that has not been set.
+    try {
+      $plugin->getContext('user');
+    }
+    catch (PluginException $e) {
+      $this->assertEqual($e->getMessage(), 'The user context is not yet set.');
+    }
+
+    // Try to call a method of the plugin that requires context before it has
+    // been set.
+    try {
+      $plugin->getTitle();
+    }
+    catch (PluginException $e) {
+      $this->assertEqual($e->getMessage(), 'The user context is not yet set.');
+    }
+
+    // Try to get a context that is not valid.
+    try {
+      $plugin->getContext('node');
+    }
+    catch (PluginException $e) {
+      $this->assertEqual($e->getMessage(), 'The node context is not a valid context.');
+    }
+
+    // Try to pass the wrong class type as a context.
+    try {
+      $plugin->setContext('user', $node);
+    }
+    catch (ContextException $e) {
+      $this->assertEqual($e->getMessage(), 'The context passed was not an instance of Drupal\plugin_test\MockUser.');
+    }
+
+    // Set an appropriate context appropriately and check to make sure its
+    // methods work as expected.
+    $user = new MockUser(array('name' => $name));
+    $plugin->setContext('user', $user);
+    $this->assertEqual($user->label(), $plugin->getTitle());
+
+    // Test the getContextDefinitions() method.
+    $this->assertIdentical($plugin->getContextDefinitions(), array('user' => 'Drupal\plugin_test\MockUser'));
+
+    // Test the getContextDefinition() method for a valid context.
+    $this->assertEqual($plugin->getContextDefinition('user'), 'Drupal\plugin_test\MockUser');
+
+    // Test the getContextDefinition() method for an invalid context.
+    try {
+      $plugin->getContextDefinition('node');
+    }
+    catch (PluginException $e) {
+      $this->assertEqual($e->getMessage(), 'The node context is not a valid context.');
+    }
+
+    // Test TypedData Context Plugins
+    $typed_data_plugin = $manager->createInstance('string_context');
+
+    // Try to get a valid context that has not been set.
+    try {
+      $typed_data_plugin->getContext('string');
+    }
+    catch (PluginException $e) {
+      $this->assertEqual($e->getMessage(), 'The string context is not yet set.');
+    }
+
+    // Try to call a method of the plugin that requires context before it has
+    // been set.
+    try {
+      $typed_data_plugin->getTitle();
+    }
+    catch (PluginException $e) {
+      $this->assertEqual($e->getMessage(), 'The string context is not yet set.');
+    }
+
+    // Set the context appropriately.
+    $typed_data_plugin->setContext('string', $name);
+    $this->assertEqual($name, $typed_data_plugin->getTitle());
+  }
+}
diff --git a/core/modules/system/lib/Drupal/system/Tests/Plugin/PluginTestBase.php b/core/modules/system/lib/Drupal/system/Tests/Plugin/PluginTestBase.php
index 5db9322..892d30c0 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Plugin/PluginTestBase.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Plugin/PluginTestBase.php
@@ -70,6 +70,20 @@ public function setUp() {
         'label' => 'Layout Foo',
         'class' => 'Drupal\plugin_test\Plugin\plugin_test\mock_block\MockLayoutBlock',
       ),
+      'user_name' => array(
+        'label' => 'User Name',
+        'class' => 'Drupal\plugin_test\Plugin\plugin_test\mock_block\MockUserNameBlock',
+        'context' => array(
+          'user' => 'Drupal\plugin_test\MockUser'
+        ),
+      ),
+      'string_context' => array(
+        'label' => 'String Typed Data',
+        'class' => 'Drupal\plugin_test\Plugin\plugin_test\mock_block\TypedDataStringBlock',
+        'context' => array(
+          'string' => array('type' => 'string'),
+        ),
+      )
     );
     $this->defaultsTestPluginExpectedDefinitions = array(
       'test_block1' => array(
diff --git a/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/MockEntity.php b/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/MockEntity.php
new file mode 100644
index 0000000..941330d
--- /dev/null
+++ b/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/MockEntity.php
@@ -0,0 +1,26 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\plugin_test\MockEntity.
+ */
+
+namespace Drupal\plugin_test;
+
+abstract class MockEntity {
+
+  /**
+   * The title of the mock entity.
+   *
+   * @var string
+   *  A string.
+   */
+  protected $title;
+
+  /**
+   * A simple label function.
+   */
+  public function label() {
+    return $this->title;
+  }
+}
diff --git a/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/MockNode.php b/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/MockNode.php
new file mode 100644
index 0000000..fba6a65
--- /dev/null
+++ b/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/MockNode.php
@@ -0,0 +1,18 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\plugin_test\MockNode.
+ */
+
+namespace Drupal\plugin_test;
+
+class MockNode extends MockEntity {
+
+  /**
+   * A simple label function.
+   */
+  public function __construct(array $values = array()) {
+    $this->title = isset($values['title']) ? $values['title'] : '';
+  }
+}
diff --git a/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/MockUser.php b/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/MockUser.php
new file mode 100644
index 0000000..374ec95
--- /dev/null
+++ b/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/MockUser.php
@@ -0,0 +1,18 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\plugin_test\MockUser.
+ */
+
+namespace Drupal\plugin_test;
+
+class MockUser extends MockEntity {
+
+  /**
+   * A simple label function.
+   */
+  public function __construct(array $values = array()) {
+    $this->title = isset($values['name']) ? $values['name'] : '';
+  }
+}
diff --git a/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/MockBlockManager.php b/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/MockBlockManager.php
index fcf1824..793c012 100644
--- a/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/MockBlockManager.php
+++ b/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/MockBlockManager.php
@@ -66,6 +66,25 @@ public function __construct() {
       'derivative' => 'Drupal\plugin_test\Plugin\plugin_test\mock_block\MockLayoutBlockDeriver',
     ));
 
+    // A block plugin that requires context to function. This block requires a
+    // user object in order to return the user name from the getTitle() method.
+    $this->discovery->setDefinition('user_name', array(
+      'label' => t('User Name'),
+      'class' => 'Drupal\plugin_test\Plugin\plugin_test\mock_block\MockUserNameBlock',
+      'context' => array(
+        'user' => 'Drupal\plugin_test\MockUser'
+      ),
+    ));
+
+    // A block plugin that requires a typed data string context to function.
+    $this->discovery->setDefinition('string_context', array(
+      'label' => t('String Typed Data'),
+      'class' => 'Drupal\plugin_test\Plugin\plugin_test\mock_block\TypedDataStringBlock',
+      'context' => array(
+        'string' => array('type' => 'string'),
+      ),
+    ));
+
     // In addition to finding all of the plugins available for a type, a plugin
     // type must also be able to create instances of that plugin. For example, a
     // specific instance of a "Main menu" menu block, configured to show just
diff --git a/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/plugin_test/mock_block/MockUserNameBlock.php b/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/plugin_test/mock_block/MockUserNameBlock.php
new file mode 100644
index 0000000..86b4365
--- /dev/null
+++ b/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/plugin_test/mock_block/MockUserNameBlock.php
@@ -0,0 +1,24 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\plugin_test\Plugin\plugin_test\mock_block\MockUserNameBlock.
+ */
+
+namespace Drupal\plugin_test\Plugin\plugin_test\mock_block;
+
+use Drupal\Core\Plugin\ContextualPluginBase;
+use Drupal\Component\Plugin\Discovery\DiscoveryInterface;
+
+/**
+ * Implementation of a user name block plugin used by Plugin API context test.
+ *
+ * @see Drupal\plugin_test\Plugin\MockBlockManager
+ */
+class MockUserNameBlock extends ContextualPluginBase {
+
+  public function getTitle() {
+    $user = $this->getContext('user');
+    return $user->label();
+  }
+}
diff --git a/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/plugin_test/mock_block/TypedDataStringBlock.php b/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/plugin_test/mock_block/TypedDataStringBlock.php
new file mode 100644
index 0000000..2c62f49
--- /dev/null
+++ b/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/plugin_test/mock_block/TypedDataStringBlock.php
@@ -0,0 +1,24 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\plugin_test\Plugin\plugin_test\mock_block\TypedDataStringBlock.
+ */
+
+namespace Drupal\plugin_test\Plugin\plugin_test\mock_block;
+
+use Drupal\Core\Plugin\ContextualPluginBase;
+
+/**
+ * Implementation of a String TypedData contextual block plugin used by Plugin
+ * API context test.
+ *
+ * @see Drupal\plugin_test\Plugin\MockBlockManager
+ */
+class TypedDataStringBlock extends ContextualPluginBase {
+
+  public function getTitle() {
+    $context = $this->getContext('string');
+    return $context->getValue();
+  }
+}