Pure-Java WAR capable of hosting git repos and exposing them with git+ssh. Basically a copy of Gerrit (http://code.google.com/p/gerrit/) - with all the review-related functionality stripped away and the dependency on a database removed (making it entirely filesystem based).
I use it for integration-testing my git client.
Just as with Gerrit, the location of the server site is passed to the war using the 'gerrit.site_path' system property (will probably rename that at some point), and the format of the directory structure and the [gerrit.site_path]/etc/gerrit.config file is just the same. My gerrit.config file is just:
[gerrit] basePath = "repos"
...and which means the server will expect to find all the repos in [gerrit.site_path]/repos