Easy SVN is a subversion browser via the Web. It's easy because only a command line svn program and Perl are required to run it; no extra software needs to be installed. After configuring the Perl script as cgi-bin program, SVN repositories can be navigated, and entries viewed for contents, history, and diffs.
Devalot is a social networking application centered around software projects. It connects the user community with the development community and encourages participation and communication. It includes all the features you've come to expect in modern Web-based applications such as tagging, comments, and a wiki, as well as features you'd expect in project tracking software such as ticketing. It has features similar to some of those found in Trac, Collaboa, GForge, Mephisto, and Typo.