All our source code is hosted in git repositories at Eclipse.
This repository contains the entire source code of the RAP platform (a.k.a. the runtime).
This repository contains the code of the Eclipse tools for RAP.
See the Incubator page for the git repositories of all RAP Incubator components.
For more information on git at Eclipse read this introduction.
Our git repositories are mirrored on github, fork us ;-).