++ Introduction
++ Available options
++ Drivers
+++ Memcache
Memcache driver stores cache records into a memcached server. Memcached is a high-performance, distributed memory object caching system. In order to use this backend, you need a memcached daemon and the memcache PECL extension.

+++ APC
The Alternative PHP Cache (APC) is a free and open opcode cache for PHP. It was conceived of to provide a free, open, and robust framework for caching and optimizing PHP intermediate code. 

The APC cache driver of Doctrine stores cache records in shared memory.

+++ Sqlite

Sqlite caching backend stores cache records into sqlite database.