Github wasn't created until 2008, and in those early days there were big limits on hosting (very limited number of repos per user, even public ones). The everything free, everything easy all you can eat buffet that you see on Github today is a much more recent change. Back in '05 almost everything OSS was on source forge and Google Code, both of which offered super easy hosting, discussions, etc.
Sourceforge was already in demise, it was slow etc. when was it that they started adding malware? Don't remember ... i however remember Chris Wnastrath travelling to europe even for relatively small developer events and sponsoring the beer events. Quite a good marketing
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Took a bit to dig up with Google their 2011 announcement that they're now also supporting Git. https://bitbucket.org/blog/bitbucket-now-rocks-git