From zero to Silex
Silex: It's the biggest microframework you'll ever use. Or maybe the most lightweight framework you'll ever use. Or it's just Symfony Junior. So what is it?
Silex is, simply, a ready-made request/response pipeline built on the Symfony components, ready for you to build... whatever. Unlike fullstack frameworks it doesn't imply a certain model or approach, and lets you define your own architecture, for better or worse.