I am looking for a PHP caching library that has multiple back-end storage adapters. For example, something that can save the cache in a file or in Memcache.

Here are some of the libraries that I have found:

* [Extensible PHP Caching Library](https://github.com/jleider/extensible-php-caching-library)
* [Stash](https://github.com/tedivm/Stash)
* [RayCache](http://raynux.com/blog/2010/08/08/raycache-an-easy-multiple-configurable-php-caching-class/)
* [Zend\_Cache](http://framework.zend.com/manual/en/zend.cache.html)
* [SabreCache](http://code.google.com/p/sabrecache/)