This document describes a bit about the working going toward OpenLayers 3.0.
OpenLayers v3 development is taking place in git, with a central repository hosted on GitHub. To contribute to development, it's important to be comfortable working with git. The help pages on GitHub provide a nice starting place for this.
The repository contains a master branch and a 2.x branch. Other branches may come and go as people work on specific features. The master branch should be the closest stable thing to OpenLayers 3.0 (and this readme should get updated before 3.0 is released). However, at any time before the 3.0 release, the master branch should not be considered stable. The 2.x branch is used to merge in changes from any ongoing development in the v2 line of development.
If you are interested in contributing, please fork the central repository, make changes, and issue a pull request. We may change the process along the way, but for now, developers with access to the subversion trunk will be able to push to the central git repository. We welcome your contributions and thank you for helping us work toward OpenLayers 3.