Not sure if others were aware of this, but I just found it.
http://fisheye.codehaus.org/browse/geoserver
Does online view and diffs of svn, and you can apply all kinds of constraints and has visual tracking of file's branch history. Quite cool. Looks like you can also subscribe to customized feeds.
Chris
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Chris Holmes
The Open Planning Project
http://topp.openplans.org