diff --git a/core/core.services.yml b/core/core.services.yml
index 23ce7bf..7531e88 100644
--- a/core/core.services.yml
+++ b/core/core.services.yml
@@ -174,7 +174,7 @@ services:
     arguments: ['@container.namespaces', '@controller_resolver', '@request', '@module_handler', '@cache.cache', '@language_manager']
   plugin.manager.menu.local_task:
     class: Drupal\Core\Menu\LocalTaskManager
-    arguments: ['@container.namespaces', '@controller_resolver', '@request', '@router.route_provider', '@module_handler']
+    arguments: ['@container.namespaces', '@controller_resolver', '@request', '@router.route_provider', '@module_handler', '@cache.cache', '@language_manager']
   request:
     class: Symfony\Component\HttpFoundation\Request
     # @TODO the synthetic setting must be uncommented whenever drupal_session_initialize()
diff --git a/core/lib/Drupal/Core/Menu/LocalTaskManager.php b/core/lib/Drupal/Core/Menu/LocalTaskManager.php
index 00837c5..17b5128 100644
--- a/core/lib/Drupal/Core/Menu/LocalTaskManager.php
+++ b/core/lib/Drupal/Core/Menu/LocalTaskManager.php
@@ -7,7 +7,10 @@
 
 namespace Drupal\Core\Menu;
 
+use Drupal\Core\Cache\CacheBackendInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
+use Drupal\Core\Language\Language;
+use Drupal\Core\Language\LanguageManager;
 use Drupal\Core\Plugin\DefaultPluginManager;
 use Drupal\Core\Routing\RouteProviderInterface;
 use Symfony\Component\HttpFoundation\Request;
@@ -63,14 +66,19 @@ class LocalTaskManager extends DefaultPluginManager {
    * @param \Drupal\Core\Routing\RouteProviderInterface $route_provider
    *   The route provider to load routes by name.
    * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
-   *   The module handler.u
+   *   The module handler.
+   * @param \Drupal\Core\Cache\CacheBackendInterface $cache
+   *   The cache backend.
+   * @param \Drupal\Core\Language\LanguageManager $language_manager
+   *   The language manager.
    */
-  public function __construct(\Traversable $namespaces, ControllerResolverInterface $controller_resolver, Request $request, RouteProviderInterface $route_provider, ModuleHandlerInterface $module_handler) {
+  public function __construct(\Traversable $namespaces, ControllerResolverInterface $controller_resolver, Request $request, RouteProviderInterface $route_provider, ModuleHandlerInterface $module_handler, CacheBackendInterface $cache, LanguageManager $language_manager) {
     parent::__construct('Plugin/Menu/LocalTask', $namespaces, array(), 'Drupal\Core\Annotation\Menu\LocalTask');
     $this->controllerResolver = $controller_resolver;
     $this->request = $request;
     $this->routeProvider = $route_provider;
     $this->alterInfo($module_handler, 'local_tasks');
+    $this->setCacheBackend($cache, $language_manager, 'local_task', array('local_task' => TRUE));
   }
 
   /**
@@ -118,64 +126,78 @@ public function getPath(LocalTaskInterface $local_task) {
   public function getLocalTasksForRoute($route_name) {
     if (!isset($this->instances[$route_name])) {
       $this->instances[$route_name] = array();
-      // @todo - optimize this lookup by compiling or caching.
-      $definitions = $this->getDefinitions();
-      // We build the hierarchy by finding all tabs that should
-      // appear on the current route.
-      $tab_root_ids = array();
-      $parents = array();
-      foreach ($definitions as $plugin_id => $task_info) {
-        if ($route_name == $task_info['route_name']) {
-          $tab_root_ids[$task_info['tab_root_id']] = TRUE;
-          // Tabs that link to the current route are viable parents
-          // and their parent and children should be visible also.
-          // @todo - this only works for 2 levels of tabs.
-          // instead need to iterate up.
-          $parents[$plugin_id] = TRUE;
-          if (!empty($task_info['tab_parent_id'])) {
-            $parents[$task_info['tab_parent_id']] = TRUE;
-          }
-        }
+      if ($cache = $this->cacheBackend->get($this->cacheKey . ':' . $route_name)) {
+        $tab_root_ids = $cache->data['tab_root_ids'];
+        $parents = $cache->data['parents'];
+        $children = $cache->data['children'];
       }
-      if ($tab_root_ids) {
-        // Find all the plugins with the same root and that are at the top
-        // level or that have a visible parent.
+      else {
+        $definitions = $this->getDefinitions();
+        // We build the hierarchy by finding all tabs that should
+        // appear on the current route.
+        $tab_root_ids = array();
+        $parents = array();
         $children = array();
-        foreach ($definitions  as $plugin_id => $task_info) {
-          if (!empty($tab_root_ids[$task_info['tab_root_id']]) && (empty($task_info['tab_parent_id']) || !empty($parents[$task_info['tab_parent_id']]))) {
-            // Concat '> ' with root ID for the parent of top-level tabs.
-            $parent = empty($task_info['tab_parent_id']) ? '> ' . $task_info['tab_root_id'] : $task_info['tab_parent_id'];
-            $children[$parent][$plugin_id] = $task_info;
+        foreach ($definitions as $plugin_id => $task_info) {
+          if ($route_name == $task_info['route_name']) {
+            $tab_root_ids[$task_info['tab_root_id']] = $task_info['tab_root_id'];
+            // Tabs that link to the current route are viable parents
+            // and their parent and children should be visible also.
+            // @todo - this only works for 2 levels of tabs.
+            // instead need to iterate up.
+            $parents[$plugin_id] = TRUE;
+            if (!empty($task_info['tab_parent_id'])) {
+              $parents[$task_info['tab_parent_id']] = TRUE;
+            }
           }
         }
-        foreach (array_keys($tab_root_ids) as $root_id) {
-          // Convert the tree keyed by plugin IDs into a simple one with
-          // integer depth.  Create instances for each plugin along the way.
-          $level = 0;
-          // We used this above as the top-level parent array key.
-          $next_parent = '> ' . $root_id;
-          do {
-            $parent = $next_parent;
-            $next_parent = FALSE;
-            foreach ($children[$parent] as $plugin_id => $task_info) {
-              $plugin = $this->createInstance($plugin_id);
-              $this->instances[$route_name][$level][$plugin_id] = $plugin;
-              // Normally, l() compares the href of every link with the current
-              // path and sets the active class accordingly. But the parents of
-              // the current local task may be on a different route in which
-              // case we have to set the class manually by flagging it active.
-              if (!empty($parents[$plugin_id]) && $route_name != $task_info['route_name']) {
-                $plugin->setActive();
-              }
-              if (isset($children[$plugin_id])) {
-                // This tab has visible children
-                $next_parent = $plugin_id;
-              }
+        if ($tab_root_ids) {
+          // Find all the plugins with the same root and that are at the top
+          // level or that have a visible parent.
+          foreach ($definitions  as $plugin_id => $task_info) {
+            if (!empty($tab_root_ids[$task_info['tab_root_id']]) && (empty($task_info['tab_parent_id']) || !empty($parents[$task_info['tab_parent_id']]))) {
+              // Concat '> ' with root ID for the parent of top-level tabs.
+              $parent = empty($task_info['tab_parent_id']) ? '> ' . $task_info['tab_root_id'] : $task_info['tab_parent_id'];
+              $children[$parent][$plugin_id] = $task_info;
             }
-            $level++;
-          } while ($next_parent);
+          }
         }
+        $data = array(
+          'tab_root_ids' => $tab_root_ids,
+          'parents' => $parents,
+          'children' => $children,
+        );
+        $this->cacheBackend->set($this->cacheKey . ':' . $route_name, $data, CacheBackendInterface::CACHE_PERMANENT, array('local_task'));
       }
+      // Create a plugin instance for each element of the hierarchy.
+      foreach ($tab_root_ids as $root_id) {
+        // Convert the tree keyed by plugin IDs into a simple one with
+        // integer depth.  Create instances for each plugin along the way.
+        $level = 0;
+        // We used this above as the top-level parent array key.
+        $next_parent = '> ' . $root_id;
+        do {
+          $parent = $next_parent;
+          $next_parent = FALSE;
+          foreach ($children[$parent] as $plugin_id => $task_info) {
+            $plugin = $this->createInstance($plugin_id);
+            $this->instances[$route_name][$level][$plugin_id] = $plugin;
+            // Normally, l() compares the href of every link with the current
+            // path and sets the active class accordingly. But the parents of
+            // the current local task may be on a different route in which
+            // case we have to set the class manually by flagging it active.
+            if (!empty($parents[$plugin_id]) && $route_name != $task_info['route_name']) {
+              $plugin->setActive();
+            }
+            if (isset($children[$plugin_id])) {
+              // This tab has visible children
+              $next_parent = $plugin_id;
+            }
+          }
+          $level++;
+        } while ($next_parent);
+      }
+
     }
     return $this->instances[$route_name];
   }
diff --git a/core/tests/Drupal/Tests/Core/Menu/LocalTaskManagerTest.php b/core/tests/Drupal/Tests/Core/Menu/LocalTaskManagerTest.php
index 5d61a9c..8ac918d 100644
--- a/core/tests/Drupal/Tests/Core/Menu/LocalTaskManagerTest.php
+++ b/core/tests/Drupal/Tests/Core/Menu/LocalTaskManagerTest.php
@@ -8,6 +8,8 @@
 namespace Drupal\Tests\Core\Menu;
 
 use Drupal\Component\Plugin\Factory\DefaultFactory;
+use Drupal\Core\Cache\CacheBackendInterface;
+use Drupal\Core\Language\Language;
 use Drupal\system\Plugin\Type\MenuLocalTaskManager;
 use Drupal\Tests\UnitTestCase;
 use Symfony\Component\HttpFoundation\Request;
@@ -23,7 +25,7 @@ class LocalTaskManagerTest extends UnitTestCase {
   /**
    * The tested manager.
    *
-   * @var \Drupal\system\Plugin\Type\MenuLocalTaskManager
+   * @var \Drupal\Core\Menu\LocalTaskManager
    */
   protected $manager;
 
@@ -62,6 +64,13 @@ class LocalTaskManagerTest extends UnitTestCase {
    */
   protected $factory;
 
+  /**
+   * The cache backend used in the test.
+   *
+   * @var \PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $cacheBackend;
+
   public static function getInfo() {
     return array(
       'name' => 'Local tasks manager.',
@@ -81,6 +90,7 @@ protected function setUp() {
     $this->routeProvider = $this->getMock('Drupal\Core\Routing\RouteProviderInterface');
     $this->pluginDiscovery = $this->getMock('Drupal\Component\Plugin\Discovery\DiscoveryInterface');
     $this->factory = $this->getMock('Drupal\Component\Plugin\Factory\FactoryInterface');
+    $this->cacheBackend = $this->getMock('Drupal\Core\Cache\CacheBackendInterface');
 
     $this->setupLocalTaskManager();
   }
@@ -91,53 +101,94 @@ protected function setUp() {
    * @see \Drupal\system\Plugin\Type\MenuLocalTaskManager::getLocalTasksForRoute()
    */
   public function testGetLocalTasksForRouteSingleLevelTitle() {
-    $definitions = array();
-    $definitions['menu_local_task_test_tasks_settings'] = array(
-      'id' => 'menu_local_task_test_tasks_settings',
-      'route_name' => 'menu_local_task_test_tasks_settings',
-      'title' => 'Settings',
-      'tab_root_id' => 'menu_local_task_test_tasks_view',
-      'class' => 'Drupal\menu_test\Plugin\Menu\MenuLocalTasksTestTasksSettings',
-    );
-    $definitions['menu_local_task_test_tasks_edit'] = array(
-      'id' => 'menu_local_task_test_tasks_edit',
-      'route_name' => 'menu_local_task_test_tasks_edit',
-      'title' => 'Settings',
-      'tab_root_id' => 'menu_local_task_test_tasks_view',
-      'class' => 'Drupal\menu_test\Plugin\Menu\MenuLocalTasksTestTasksEdit',
-      'weight' => 20,
-    );
-    $definitions['menu_local_task_test_tasks_view'] = array(
-      'id' => 'menu_local_task_test_tasks_view',
-      'route_name' => 'menu_local_task_test_tasks_view',
-      'title' => 'Settings',
-      'tab_root_id' => 'menu_local_task_test_tasks_view',
-      'class' => 'Drupal\menu_test\Plugin\Menu\MenuLocalTasksTestTasksView',
-    );
+    $definitions = $this->getLocalTaskFixtures();
 
-    $this->pluginDiscovery->expects($this->any())
+    $this->pluginDiscovery->expects($this->once())
       ->method('getDefinitions')
       ->will($this->returnValue($definitions));
 
     $mock_plugin = $this->getMock('Drupal\Core\Menu\LocalTaskInterface');
 
-    $map = array(
-      array('menu_local_task_test_tasks_settings', array(), $mock_plugin),
-      array('menu_local_task_test_tasks_edit', array(), $mock_plugin),
-      array('menu_local_task_test_tasks_view', array(), $mock_plugin),
+    $this->setupFactory($mock_plugin);
+    $this->setupLocalTaskManager();
+
+    $local_tasks = $this->manager->getLocalTasksForRoute('menu_local_task_test_tasks_view');
+
+    $result = array(
+      0 => array(
+        'menu_local_task_test_tasks_settings' => $mock_plugin,
+        'menu_local_task_test_tasks_view' => $mock_plugin,
+        'menu_local_task_test_tasks_edit' => $mock_plugin,
+      )
     );
-    $this->factory->expects($this->any())
-      ->method('createInstance')
-      ->will($this->returnValueMap($map));
+
+    $this->assertEquals($result, $local_tasks);
+  }
+
+  /**
+   * Tests the cache of the local task manager with an empty initial cache.
+   */
+  public function testGetLocalTaskForRouteWithEmptyCache() {
+    $definitions = $this->getLocalTaskFixtures();
+
+    $this->pluginDiscovery->expects($this->once())
+      ->method('getDefinitions')
+      ->will($this->returnValue($definitions));
+
+    $mock_plugin = $this->getMock('Drupal\Core\Menu\LocalTaskInterface');
+    $this->setupFactory($mock_plugin);
 
     $this->setupLocalTaskManager();
 
+    $result = $this->getLocalTasksForRouteResult($mock_plugin);
+
+    $this->cacheBackend->expects($this->at(0))
+      ->method('get')
+      ->with('local_task:en:menu_local_task_test_tasks_view');
+
+    $this->cacheBackend->expects($this->at(1))
+      ->method('get')
+      ->with('local_task:en');
+
+    $this->cacheBackend->expects($this->at(2))
+      ->method('set')
+      ->with('local_task:en', $definitions, CacheBackendInterface::CACHE_PERMANENT);
+
+    $expected_set = $this->getLocalTasksCache();
+
+    $this->cacheBackend->expects($this->at(3))
+      ->method('set')
+      ->with('local_task:en:menu_local_task_test_tasks_view', $expected_set, CacheBackendInterface::CACHE_PERMANENT, array('local_task'));
+
     $local_tasks = $this->manager->getLocalTasksForRoute('menu_local_task_test_tasks_view');
-    $this->assertEquals(array(0 => array(
-      'menu_local_task_test_tasks_settings' => $mock_plugin,
-      'menu_local_task_test_tasks_view' => $mock_plugin,
-      'menu_local_task_test_tasks_edit' => $mock_plugin,
-    )), $local_tasks);
+    $this->assertEquals($result, $local_tasks);
+  }
+
+  /**
+   * Tests the cache of the local task manager with a filled initial cache.
+   */
+  public function testGetLocalTaskForRouteWithFilledCache() {
+    $this->pluginDiscovery->expects($this->never())
+      ->method('getDefinitions');
+
+    $mock_plugin = $this->getMock('Drupal\Core\Menu\LocalTaskInterface');
+    $this->setupFactory($mock_plugin);
+
+    $this->setupLocalTaskManager();
+
+    $result = $this->getLocalTasksCache($mock_plugin);
+
+    $this->cacheBackend->expects($this->at(0))
+      ->method('get')
+      ->with('local_task:en:menu_local_task_test_tasks_view')
+      ->will($this->returnValue((object) array('data' => $result)));
+
+    $this->cacheBackend->expects($this->never())
+      ->method('set');
+
+    $result = $this->getLocalTasksForRouteResult($mock_plugin);
+    $local_tasks = $this->manager->getLocalTasksForRoute('menu_local_task_test_tasks_view');
+    $this->assertEquals($result, $local_tasks);
   }
 
   /**
@@ -201,6 +252,104 @@ protected function setupLocalTaskManager() {
     $property = new \ReflectionProperty('Drupal\Core\Menu\LocalTaskManager', 'factory');
     $property->setAccessible(TRUE);
     $property->setValue($this->manager, $this->factory);
+
+    $language_manager = $this->getMockBuilder('Drupal\Core\Language\LanguageManager')
+      ->disableOriginalConstructor()
+      ->getMock();
+    $language_manager->expects($this->any())
+      ->method('getLanguage')
+      ->will($this->returnValue(new Language(array('id' => 'en'))));
+
+    $this->manager->setCacheBackend($this->cacheBackend, $language_manager, 'local_task');
+  }
+
+  /**
+   * Return some local tasks plugin definitions.
+   *
+   * @return array
+   *   An array of plugin definition keyed by plugin ID.
+   */
+  protected function getLocalTaskFixtures() {
+    $definitions = array();
+    $definitions['menu_local_task_test_tasks_settings'] = array(
+      'id' => 'menu_local_task_test_tasks_settings',
+      'route_name' => 'menu_local_task_test_tasks_settings',
+      'title' => 'Settings',
+      'tab_root_id' => 'menu_local_task_test_tasks_view',
+      'class' => 'Drupal\menu_test\Plugin\Menu\MenuLocalTasksTestTasksSettings',
+    );
+    $definitions['menu_local_task_test_tasks_edit'] = array(
+      'id' => 'menu_local_task_test_tasks_edit',
+      'route_name' => 'menu_local_task_test_tasks_edit',
+      'title' => 'Settings',
+      'tab_root_id' => 'menu_local_task_test_tasks_view',
+      'class' => 'Drupal\menu_test\Plugin\Menu\MenuLocalTasksTestTasksEdit',
+      'weight' => 20,
+    );
+    $definitions['menu_local_task_test_tasks_view'] = array(
+      'id' => 'menu_local_task_test_tasks_view',
+      'route_name' => 'menu_local_task_test_tasks_view',
+      'title' => 'Settings',
+      'tab_root_id' => 'menu_local_task_test_tasks_view',
+      'class' => 'Drupal\menu_test\Plugin\Menu\MenuLocalTasksTestTasksView',
+    );
+    return $definitions;
+  }
+
+  /**
+   * Setups the plugin factory with some local task plugins.
+   *
+   * @param \PHPUnit_Framework_MockObject_MockObject $mock_plugin
+   *   The mock plugin.
+   */
+  protected function setupFactory($mock_plugin) {
+    $map = array(
+      array('menu_local_task_test_tasks_settings', array(), $mock_plugin),
+      array('menu_local_task_test_tasks_edit', array(), $mock_plugin),
+      array('menu_local_task_test_tasks_view', array(), $mock_plugin),
+    );
+    $this->factory->expects($this->any())
+      ->method('createInstance')
+      ->will($this->returnValueMap($map));
+  }
+
+  /**
+   * Returns an expected result for getLocalTasksForRoute.
+   *
+   * @param \PHPUnit_Framework_MockObject_MockObject $mock_plugin
+   *   The mock plugin.
+   *
+   * @return array
+   *   The expected result, keyed by local task leve.
+   */
+  protected function getLocalTasksForRouteResult($mock_plugin) {
+    $result = array(
+      0 => array(
+        'menu_local_task_test_tasks_settings' => $mock_plugin,
+        'menu_local_task_test_tasks_view' => $mock_plugin,
+        'menu_local_task_test_tasks_edit' => $mock_plugin,
+      )
+    );
+    return $result;
+  }
+
+  /**
+   * Returns the cache entry expected when running getLocalTaskForRoute().
+   *
+   * @return array
+   */
+  protected function getLocalTasksCache() {
+    return array(
+      'tab_root_ids' => array(
+        'menu_local_task_test_tasks_view' => 'menu_local_task_test_tasks_view',
+      ),
+      'parents' => array(
+        'menu_local_task_test_tasks_view' => 1,
+      ),
+      'children' => array(
+        '> menu_local_task_test_tasks_view' => $this->getLocalTaskFixtures(),
+      )
+    );
   }
 
 }