URLMapper Service
With this service you can control the pathinfo or query part of a URL (what's behind the webapproot and the context) using a mapping (routing) file. The format may be xml, json or yaml. That is, you define what URL you want to match (using default placeholders) and how it will resolve to the expected parameters. Most importantly you should map your action self!
Configuration and Usage
Find further information in URL Mapper Howto.