diff --git a/includes/cache-install.inc b/includes/cache-install.inc
deleted file mode 100644
index 8bcf8b7..0000000
--- a/includes/cache-install.inc
+++ /dev/null
@@ -1,68 +0,0 @@
-<?php
-
-/**
- * @file
- * Provides a stub cache implementation to be used during installation.
- */
-
-/**
- * A stub cache implementation to be used during the installation process.
- *
- * The stub implementation is needed when database access is not yet available.
- * Because Drupal's caching system never requires that cached data be present,
- * these stub functions can short-circuit the process and sidestep the need for
- * any persistent storage. Obviously, using this cache implementation during
- * normal operations would have a negative impact on performance.
- */
-class DrupalFakeCache extends DrupalDatabaseCache implements DrupalCacheInterface {
-  function get($cid) {
-    return FALSE;
-  }
-
-  function getMultiple(&$cids) {
-    return array();
-  }
-
-  function set($cid, $data, $expire = CACHE_PERMANENT) {
-  }
-
-  function deletePrefix($cid) {
-    try {
-      if (class_exists('Database')) {
-        parent::deletePrefix($cid);
-      }
-    }
-    catch (Exception $e) {
-    }
-  }
-
-  function clear($cid = NULL, $wildcard = FALSE) {
-    // If there is a database cache, attempt to clear it whenever possible. The
-    // reason for doing this is that the database cache can accumulate data
-    // during installation due to any full bootstraps that may occur at the
-    // same time (for example, Ajax requests triggered by the installer). If we
-    // didn't try to clear it whenever this function is called, the data in the
-    // cache would become stale; for example, the installer sometimes calls
-    // variable_set(), which updates the {variable} table and then clears the
-    // cache to make sure that the next page request picks up the new value.
-    // Not actually clearing the cache here therefore leads old variables to be
-    // loaded on the first page requests after installation, which can cause
-    // subtle bugs, some of which would not be fixed unless the site
-    // administrator cleared the cache manually.
-    try {
-      if (class_exists('Database')) {
-        parent::clear($cid, $wildcard);
-      }
-    }
-    // If the attempt at clearing the cache causes an error, that means that
-    // either the database connection is not set up yet or the relevant cache
-    // table in the database has not yet been created, so we can safely do
-    // nothing here.
-    catch (Exception $e) {
-    }
-  }
-
-  function isEmpty() {
-    return TRUE;
-  }
-}
diff --git a/includes/cache.inc b/includes/cache.inc
index fcf3e5e..a748a69 100644
--- a/includes/cache.inc
+++ b/includes/cache.inc
@@ -1,18 +1,21 @@
 <?php
 
 /**
- * Factory for instantiating and statically caching the correct class for a cache bin.
+ * Factory for instantiating and statically caching the correct class for a
+ * cache bin.
  *
- * By default, this returns an instance of the DrupalDatabaseCache class.
- * Classes implementing DrupalCacheInterface can register themselves both as a
- * default implementation and for specific bins.
+ * By default, this returns an instance of the Drupal\Cache\DatabaseBackend
+ * class.
+ * 
+ * Classes implementing Drupal\Cache\BackendInterface can register themselves
+ * both as a default implementation and for specific bins.
  *
- * @see DrupalCacheInterface
+ * @see Drupal\Cache\BackendInterface
  *
  * @param $bin
  *   The cache bin for which the cache object should be returned, defaults to
  *   'cache'.
- * @return DrupalCacheInterface
+ * @return Drupal\Cache\BackendInterface
  *   The cache object associated with the specified bin.
  */
 function cache($bin = 'cache') {
@@ -26,7 +29,7 @@ function cache($bin = 'cache') {
   if (!isset($cache_objects[$bin])) {
     $class = variable_get('cache_class_' . $bin);
     if (!isset($class)) {
-      $class = variable_get('cache_default_class', 'DrupalDatabaseCache');
+      $class = variable_get('cache_default_class', 'Drupal\\Cache\\DatabaseBackend');
     }
     $cache_objects[$bin] = new $class($bin);
   }
@@ -188,431 +191,3 @@ function cache_clear_all($cid = NULL, $bin = NULL, $wildcard = FALSE) {
 function cache_is_empty($bin) {
   return cache($bin)->isEmpty();
 }
-
-/**
- * Interface for cache implementations.
- *
- * All cache implementations have to implement this interface.
- * DrupalDatabaseCache provides the default implementation, which can be
- * consulted as an example.
- *
- * To make Drupal use your implementation for a certain cache bin, you have to
- * set a variable with the name of the cache bin as its key and the name of
- * your class as its value. For example, if your implementation of
- * DrupalCacheInterface was called MyCustomCache, the following line would make
- * Drupal use it for the 'cache_page' bin:
- * @code
- *  variable_set('cache_class_cache_page', 'MyCustomCache');
- * @endcode
- *
- * Additionally, you can register your cache implementation to be used by
- * default for all cache bins by setting the variable 'cache_default_class' to
- * the name of your implementation of the DrupalCacheInterface, e.g.
- * @code
- *  variable_set('cache_default_class', 'MyCustomCache');
- * @endcode
- *
- * To implement a completely custom cache bin, use the same variable format:
- * @code
- *  variable_set('cache_class_custom_bin', 'MyCustomCache');
- * @endcode
- * To access your custom cache bin, specify the name of the bin when storing
- * or retrieving cached data:
- * @code
- *  cache_set($cid, $data, 'custom_bin', $expire);
- *  cache_get($cid, 'custom_bin');
- * @endcode
- *
- * @see cache()
- * @see DrupalDatabaseCache
- */
-interface DrupalCacheInterface {
-  /**
-   * Constructor.
-   *
-   * @param $bin
-   *   The cache bin for which the object is created.
-   */
-  function __construct($bin);
-
-  /**
-   * Return data from the persistent cache. Data may be stored as either plain
-   * text or as serialized data. cache_get will automatically return
-   * unserialized objects and arrays.
-   *
-   * @param $cid
-   *   The cache ID of the data to retrieve.
-   * @return
-   *   The cache or FALSE on failure.
-   */
-  function get($cid);
-
-  /**
-   * Return data from the persistent cache when given an array of cache IDs.
-   *
-   * @param $cids
-   *   An array of cache IDs for the data to retrieve. This is passed by
-   *   reference, and will have the IDs successfully returned from cache
-   *   removed.
-   * @return
-   *   An array of the items successfully returned from cache indexed by cid.
-   */
-   function getMultiple(&$cids);
-
-  /**
-   * Store data in the persistent cache.
-   *
-   * @param $cid
-   *   The cache ID of the data to store.
-   * @param $data
-   *   The data to store in the cache. Complex data types will be automatically
-   *   serialized before insertion.
-   *   Strings will be stored as plain text and not serialized.
-   * @param $expire
-   *   One of the following values:
-   *   - CACHE_PERMANENT: Indicates that the item should never be removed unless
-   *     explicitly told to using cache_clear_all() with a cache ID.
-   *   - CACHE_TEMPORARY: Indicates that the item should be removed at the next
-   *     general cache wipe.
-   *   - A Unix timestamp: Indicates that the item should be kept at least until
-   *     the given time, after which it behaves like CACHE_TEMPORARY.
-   */
-  function set($cid, $data, $expire = CACHE_PERMANENT);
-
-  /**
-   * Delete an item from the cache.
-   *
-   * @param $cid
-   *    The cache ID to delete.
-   */
-  function delete($cid);
-
-  /**
-   * Delete multiple items from the cache.
-   *
-   * @param $cids
-   *   An array of $cids to delete.
-   */
-  function deleteMultiple(Array $cids);
-
-  /**
-   * Delete items from the cache using a wildcard prefix.
-   *
-   * @param $prefix
-   *   A wildcard prefix.
-   */
-  function deletePrefix($prefix);
-
-  /**
-   * Flush all cache items in a bin.
-   */
-  function flush();
-
-  /**
-   * Expire temporary items from cache.
-   */
-  function expire();
-
-  /**
-   * Perform garbage collection on a cache bin.
-   */
-  function garbageCollection();
-
-  /**
-   * Expire data from the cache. If called without arguments, expirable
-   * entries will be cleared from the cache_page and cache_block bins.
-   *
-   * @param $cid
-   *   If set, the cache ID to delete. Otherwise, all cache entries that can
-   *   expire are deleted.
-   * @param $wildcard
-   *   If set to TRUE, the $cid is treated as a substring
-   *   to match rather than a complete ID. The match is a right hand
-   *   match. If '*' is given as $cid, the bin $bin will be emptied.
-   *
-   * @todo: this method is deprecated, as it's functionality is covered by
-   * more targeted methods in the interface.
-   */
-  function clear($cid = NULL, $wildcard = FALSE);
-
-  /**
-   * Check if a cache bin is empty.
-   *
-   * A cache bin is considered empty if it does not contain any valid data for
-   * any cache ID.
-   *
-   * @return
-   *   TRUE if the cache bin specified is empty.
-   */
-  function isEmpty();
-}
-
-/**
- * A stub cache implementation.
- *
- * The stub implementation is needed when database access is not yet available.
- * Because Drupal's caching system never requires that cached data be present,
- * these stub functions can short-circuit the process and sidestep the need for
- * any persistent storage. Using this cache implementation during normal
- * operations would have a negative impact on performance.
- *
- * This also can be used for testing purposes.
- */
-class DrupalNullCache implements DrupalCacheInterface {
-
-  function __construct($bin) {}
-
-  function get($cid) {
-    return FALSE;
-  }
-
-  function getMultiple(&$cids) {
-    return array();
-  }
-
-  function set($cid, $data, $expire = CACHE_PERMANENT) {}
-
-  function delete($cid) {}
-
-  function deleteMultiple(array $cids) {}
-
-  function deletePrefix($prefix) {}
-
-  function flush() {}
-
-  function expire() {}
-
-  function garbageCollection() {}
-
-  function clear($cid = NULL, $wildcard = FALSE) {}
-
-  function isEmpty() {
-    return TRUE;
-  }
-}
-
-/**
- * Default cache implementation.
- *
- * This is Drupal's default cache implementation. It uses the database to store
- * cached data. Each cache bin corresponds to a database table by the same name.
- */
-class DrupalDatabaseCache implements DrupalCacheInterface {
-  protected $bin;
-
-  function __construct($bin) {
-    // All cache tables should be prefixed with 'cache_', apart from the
-    // default 'cache' bin, which would look silly.
-    if ($bin != 'cache') {
-      $bin = 'cache_' . $bin;
-    }
-    $this->bin = $bin;
-  }
-
-  function get($cid) {
-    $cids = array($cid);
-    $cache = $this->getMultiple($cids);
-    return reset($cache);
-  }
-
-  function getMultiple(&$cids) {
-    try {
-      // Garbage collection necessary when enforcing a minimum cache lifetime.
-      $this->garbageCollection($this->bin);
-
-      // When serving cached pages, the overhead of using db_select() was found
-      // to add around 30% overhead to the request. Since $this->bin is a
-      // variable, this means the call to db_query() here uses a concatenated
-      // string. This is highly discouraged under any other circumstances, and
-      // is used here only due to the performance overhead we would incur
-      // otherwise. When serving an uncached page, the overhead of using
-      // db_select() is a much smaller proportion of the request.
-      $result = db_query('SELECT cid, data, created, expire, serialized FROM {' . db_escape_table($this->bin) . '} WHERE cid IN (:cids)', array(':cids' => $cids));
-      $cache = array();
-      foreach ($result as $item) {
-        $item = $this->prepareItem($item);
-        if ($item) {
-          $cache[$item->cid] = $item;
-        }
-      }
-      $cids = array_diff($cids, array_keys($cache));
-      return $cache;
-    }
-    catch (Exception $e) {
-      // If the database is never going to be available, cache requests should
-      // return FALSE in order to allow exception handling to occur.
-      return array();
-    }
-  }
-
-  /**
-   * Prepare a cached item.
-   *
-   * Checks that items are either permanent or did not expire, and unserializes
-   * data as appropriate.
-   *
-   * @param $cache
-   *   An item loaded from cache_get() or cache_get_multiple().
-   * @return
-   *   The item with data unserialized as appropriate or FALSE if there is no
-   *   valid item to load.
-   */
-  protected function prepareItem($cache) {
-    global $user;
-
-    if (!isset($cache->data)) {
-      return FALSE;
-    }
-    // If enforcing a minimum cache lifetime, validate that the data is
-    // currently valid for this user before we return it by making sure the cache
-    // entry was created before the timestamp in the current session's cache
-    // timer. The cache variable is loaded into the $user object by _drupal_session_read()
-    // in session.inc. If the data is permanent or we're not enforcing a minimum
-    // cache lifetime always return the cached data.
-    if ($cache->expire != CACHE_PERMANENT && variable_get('cache_lifetime', 0) && $user->cache > $cache->created) {
-      // This cache data is too old and thus not valid for us, ignore it.
-      return FALSE;
-    }
-
-    if ($cache->serialized) {
-      $cache->data = unserialize($cache->data);
-    }
-
-    return $cache;
-  }
-
-  function set($cid, $data, $expire = CACHE_PERMANENT) {
-    $fields = array(
-      'serialized' => 0,
-      'created' => REQUEST_TIME,
-      'expire' => $expire,
-    );
-    if (!is_string($data)) {
-      $fields['data'] = serialize($data);
-      $fields['serialized'] = 1;
-    }
-    else {
-      $fields['data'] = $data;
-      $fields['serialized'] = 0;
-    }
-
-    try {
-      db_merge($this->bin)
-        ->key(array('cid' => $cid))
-        ->fields($fields)
-        ->execute();
-    }
-    catch (Exception $e) {
-      // The database may not be available, so we'll ignore cache_set requests.
-    }
-  }
-
-  function delete($cid) {
-    db_delete($this->bin)
-      ->condition('cid', $cid)
-      ->execute();
-  }
-
-  function deleteMultiple(Array $cids) {
-    // Delete in chunks when a large array is passed.
-    do {
-      db_delete($this->bin)
-        ->condition('cid', array_splice($cids, 0, 1000), 'IN')
-        ->execute();
-    }
-    while (count($cids));
-  }
-
-  function deletePrefix($prefix) {
-    db_delete($this->bin)
-      ->condition('cid', db_like($prefix) . '%', 'LIKE')
-      ->execute();
-  }
-
-  function flush() {
-    db_truncate($this->bin)->execute();
-  }
-
-  function expire() {
-    if (variable_get('cache_lifetime', 0)) {
-      // We store the time in the current user's $user->cache variable which
-      // will be saved into the sessions bin by _drupal_session_write(). We then
-      // simulate that the cache was flushed for this user by not returning
-      // cached data that was cached before the timestamp.
-      $GLOBALS['user']->cache = REQUEST_TIME;
-
-      $cache_flush = variable_get('cache_flush_' . $this->bin, 0);
-      if ($cache_flush == 0) {
-        // This is the first request to clear the cache, start a timer.
-        variable_set('cache_flush_' . $this->bin, REQUEST_TIME);
-      }
-      elseif (REQUEST_TIME > ($cache_flush + variable_get('cache_lifetime', 0))) {
-        // Clear the cache for everyone, cache_lifetime seconds have
-        // passed since the first request to clear the cache.
-        db_delete($this->bin)
-          ->condition('expire', CACHE_PERMANENT, '<>')
-          ->condition('expire', REQUEST_TIME, '<')
-          ->execute();
-        variable_set('cache_flush_' . $this->bin, 0);
-      }
-    }
-    else {
-      // No minimum cache lifetime, flush all temporary cache entries now.
-      db_delete($this->bin)
-        ->condition('expire', CACHE_PERMANENT, '<>')
-        ->condition('expire', REQUEST_TIME, '<')
-        ->execute();
-    }
-  }
-
-  function garbageCollection() {
-    global $user;
-
-    // When cache lifetime is in force, avoid running garbage collection too
-    // often since this will remove temporary cache items indiscriminately.
-    $cache_flush = variable_get('cache_flush_' . $this->bin, 0);
-    if ($cache_flush && ($cache_flush + variable_get('cache_lifetime', 0) <= REQUEST_TIME)) {
-      // Reset the variable immediately to prevent a meltdown in heavy load situations.
-      variable_set('cache_flush_' . $this->bin, 0);
-      // Time to flush old cache data
-      db_delete($this->bin)
-        ->condition('expire', CACHE_PERMANENT, '<>')
-        ->condition('expire', $cache_flush, '<=')
-        ->execute();
-    }
-  }
-
-  function clear($cid = NULL, $wildcard = FALSE) {
-    global $user;
-
-    if (empty($cid)) {
-      $this->expire();
-    }
-    else {
-      if ($wildcard) {
-        if ($cid == '*') {
-          $this->flush();
-        }
-        else {
-          $this->deletePrefix($cid);
-        }
-      }
-      elseif (is_array($cid)) {
-        $this->deleteMultiple($cid);
-      }
-      else {
-        $this->delete($cid);
-      }
-    }
-  }
-
-  function isEmpty() {
-    $this->garbageCollection();
-    $query = db_select($this->bin);
-    $query->addExpression('1');
-    $result = $query->range(0, 1)
-      ->execute()
-      ->fetchField();
-    return empty($result);
-  }
-}
diff --git a/includes/install.core.inc b/includes/install.core.inc
index 4bf4bc7..409f800 100644
--- a/includes/install.core.inc
+++ b/includes/install.core.inc
@@ -253,6 +253,21 @@ function install_begin_request(&$install_state) {
   // Set up $language, so t() caller functions will still work.
   drupal_language_initialize();
 
+  // Hook up the Symfony ClassLoader for loading PSR-0-compatible classes.
+  require_once(DRUPAL_ROOT . '/includes/Symfony/Component/ClassLoader/UniversalClassLoader.php');
+  $loader = new \Symfony\Component\ClassLoader\UniversalClassLoader();
+
+  // Register classes with namespaces.
+  $loader->registerNamespaces(array(
+    // All Symfony-borrowed code lives in /includes/Symfony.
+    'Symfony' => DRUPAL_ROOT . '/includes',
+    // All Drupal-namespaced code in core lives in /includes/Drupal.
+    'Drupal' => DRUPAL_ROOT . '/includes',
+  ));
+
+  // Activate the autoloader.
+  $loader->register();
+
   require_once DRUPAL_ROOT . '/includes/ajax.inc';
   $module_list['system']['filename'] = 'modules/system/system.module';
   $module_list['entity']['filename'] = 'modules/entity/entity.module';
@@ -272,8 +287,7 @@ function install_begin_request(&$install_state) {
   // because any data put in the cache during the installer is inherently
   // suspect, due to the fact that Drupal is not fully set up yet.
   require_once DRUPAL_ROOT . '/includes/cache.inc';
-  require_once DRUPAL_ROOT . '/includes/cache-install.inc';
-  $conf['cache_default_class'] = 'DrupalFakeCache';
+  $conf['cache_default_class'] = 'Drupal\\Cache\\InstallBackend';
 
   // Prepare for themed output. We need to run this at the beginning of the
   // page request to avoid a different theme accidentally getting set. (We also