Theres actually programs created for the sole purpose of making that easy: SVN and CVS, svn being newer. It's how projects like DCME and TWCore allow people to collaborate, and there are even special web applications you can use to set up a project page.
That was just my hairbrained theory that came out of the undo!@#$%^&*ented *sendto command. I talked to DoCk> about it whenever that was ago and he said they just use it for in-game redirects when they are getting DDos'd, so they really only use one subgame.exe at a time.