VersionPress : VersionPress is a free and open source version control plugin for WordPress built on Git. You can:
Undo changes
Create staging sites
Merge databases ...
Gerrit : Web based code review and project management for Git based projects.
Keep a Changelog : Don’t let your friends dump git logs into changelogs.
Git Reference : This is the Git reference site. It is meant to be a quick reference for learning and remembering the most important and commonly used Git commands.
Git Extensions is the only graphical user interface for Git that allows you control Git without using the commandline. It comes with a manual and video tutorials to get you started quickly.