Stan Lemon writes on the Aura Project for PHP 5.4+ blog about an experiment he's trying:
I was recently working on a small project that used Silex. As I browsed my vendor folder, I realized how much extra “stuff” I had inherited with Silex. There were a bunch of other components required when all I wanted was some quick and easy routing, micro-framework style.
When I think about going lean I always find myself coming back to Aura. Micro-frameworks are not a new to idea to Aura, so I wondered if I could take the elegance and ease of Silex by wrapping up Aura.Router and exposing it through a similar API. The result is Aura.Micro, a light wrapper for Aura.Router to get a Silex-style API.
Read the whole thing here: Aura.Micro -- Experimental Replacement for Silex.