Shamelessly copied and pasted from the news at CPHL:
Marathon development site is now active @ sourceforge.sourceforge.net/project/?group_id=1997
When propagated, it will be marathon.sourceforge.net
Coders please register w/ sourceforge and then PM or e'mail me (zin@clanplaid.net) your SourceForge login to get added to the team.
Included privs are shell access, web based access to the code and various mods, CVS, etc.
While I regret not having the time to delve into the source myself, this at least gives us a place to step in later, and keep an eye on things in the meantime. Definitely a site to keep your eye on if you still revere Marathon.