diff --git a/phpBB/docs/coding-guidelines.html b/phpBB/docs/coding-guidelines.html
index bce65335d6..3f72ac406a 100644
--- a/phpBB/docs/coding-guidelines.html
+++ b/phpBB/docs/coding-guidelines.html
@@ -240,6 +240,10 @@ PHPBB_ACM_MEMCACHE_PORT     (overwrite memcached port, default is 11211)
 PHPBB_ACM_MEMCACHE_COMPRESS (overwrite memcached compress setting, default is disabled)
 PHPBB_ACM_MEMCACHE_HOST     (overwrite memcached host name, default is localhost)
 
+PHPBB_ACM_REDIS_HOST        (overwrite redis host name, default is localhost)
+PHPBB_ACM_REDIS_PORT        (overwrite redis port, default is 6379)
+PHPBB_ACM_REDIS_PASSWORD    (overwrite redis password, default is empty)
+
 PHPBB_QA                   (Set board to QA-Mode, which means the updater also checks for RC-releases)
 </pre></div>
 
diff --git a/phpBB/includes/acm/acm_redis.php b/phpBB/includes/acm/acm_redis.php
new file mode 100644
index 0000000000..3f0e590d0a
--- /dev/null
+++ b/phpBB/includes/acm/acm_redis.php
@@ -0,0 +1,142 @@
+<?php
+/**
+*
+* @package acm
+* @version $Id$
+* @copyright (c) 2005, 2011 phpBB Group
+* @license http://opensource.org/licenses/gpl-license.php GNU Public License
+*
+*/
+
+/**
+* @ignore
+*/
+if (!defined('IN_PHPBB'))
+{
+	exit;
+}
+
+// Include the abstract base
+if (!class_exists('acm_memory'))
+{
+	require("{$phpbb_root_path}includes/acm/acm_memory.$phpEx");
+}
+
+if (!defined('PHPBB_ACM_REDIS_PORT'))
+{
+	define('PHPBB_ACM_REDIS_PORT', 6379);
+}
+
+if (!defined('PHPBB_ACM_REDIS_HOST'))
+{
+	define('PHPBB_ACM_REDIS_HOST', 'localhost');
+}
+
+if (!defined('PHPBB_ACM_REDIS'))
+{
+	//can define multiple servers with host1/port1,host2/port2 format
+	define('PHPBB_ACM_REDIS', PHPBB_ACM_REDIS_HOST . '/' . PHPBB_ACM_REDIS_PORT);
+}
+
+/**
+* ACM for Redis
+* @package acm
+*/
+class acm extends acm_memory
+{
+	var $extension = 'redis';
+
+	var $redis;
+
+	function acm()
+	{
+		// Call the parent constructor
+		parent::acm_memory();
+
+		if (!extension_loaded('redis'))
+		{
+			trigger_error("Could not find required extension [{$this->extension}] for the ACM module $acm_type.", E_USER_ERROR);
+		}
+		
+		$this->redis = new Redis();
+		foreach (explode(',', PHPBB_ACM_REDIS) as $u)
+		{
+			$parts = explode('/', $u);
+			$this->redis->connect(trim($parts[0]), trim($parts[1]));
+		}
+		
+		if (defined('PHPBB_ACM_REDIS_PASSWORD'))
+		{
+			if (!$this->redis->auth(PHPBB_ACM_REDIS_PASSWORD))
+			{
+				trigger_error("Incorrect password for the ACM module $acm_type.", E_USER_ERROR);
+			}
+		}
+	}
+
+	/**
+	* Unload the cache resources
+	*
+	* @return void
+	*/
+	function unload()
+	{
+		parent::unload();
+
+		$this->redis->close();
+	}
+
+	/**
+	* Purge cache data
+	*
+	* @return void
+	*/
+	function purge()
+	{
+		$this->redis->flushDB();
+
+		parent::purge();
+	}
+
+	/**
+	* Fetch an item from the cache
+	*
+	* @access protected
+	* @param string $var Cache key
+	* @return mixed Cached data
+	*/
+	function _read($var)
+	{
+		return $this->redis->get($this->key_prefix . $var);
+	}
+
+	/**
+	* Store data in the cache
+	*
+	* @access protected
+	* @param string $var Cache key
+	* @param mixed $data Data to store
+	* @param int $ttl Time-to-live of cached data
+	* @return bool True if the operation succeeded
+	*/
+	function _write($var, $data, $ttl = 2592000)
+	{
+		return $this->redis->setex($this->key_prefix . $var, $ttl, $data);
+	}
+
+	/**
+	* Remove an item from the cache
+	*
+	* @access protected
+	* @param string $var Cache key
+	* @return bool True if the operation succeeded
+	*/
+	function _delete($var)
+	{
+		if ($this->redis->delete($this->key_prefix . $var) > 0)
+		{
+			return true;
+		}
+		return false;
+	}
+}