The code might be much worse than anything they would have written themselves. http://en.wikipedia.org/wiki/GNU_Savannah explains they started with a fork of the SourceForge code, and they seem to still be on it (the Python/Django rewrite isn't complete). It's not obvious what SourceForge was written in, but http://sourceforge.net/apps/trac/sourceforge/wiki/Open%20Sou... shows an awful lot of PHP dependencies, and the site dates back to 1999, a time when the worst of PHP's myriad design flaws (such as register_globals and magic_quotes) were widely embraced.