Trac

http://trac-hacks.org/wiki/GitPlugin This is a plugin for Trac 0.10/0.11 which enables GIT to be used instead of Subversion for the trac:VersioningSystemBackend. [ I haven’t tested it, but it appears to be used at code.reddit.com ]

http://code.reddit.com/ Interesting to look when u have a time. PS: looks like they are using git and found a way to integrate it into Trac, which is pretty cool