awesome-php.md

@@ -35,6 +35,7 @@ A list of amazingly awesome PHP libraries, resources and shiny things.
 
 * [Silex](http://silex.sensiolabs.org/) - A micro framework built around Symfony2 components.
 * [Silex Skeleton](https://github.com/fabpot/Silex-Skeleton) - A skeleton for Silex.
+* [Stack](https://github.com/stackphp) - A library of stackable middleware for Silex/Symfony.
 * [Slim](http://www.slimframework.com/) - Another simple micro framework.
 * [Bullet PHP](http://bulletphp.com/) - A mico framework for building REST APIs.