FOSRest
This library provides various tools to rapidly develop RESTful APIs: http://github.com/FriendsOfSymfony/FOSRest
The main goals for now are to provide ways for decoding request bodies and request format negotiation (inspired by Apache mod_negotiation)
Deprecated in favor of https://github.com/willdurand/Negotiation and https://github.com/FriendsOfSymfony/FOSRestBundle