While reading up on the 'infamous' GoogleX display, I saw this post at the google blog about Google:Code.
Code.google.com is our site for external developers interested in Google-related development. It's where we'll publish free source code and lists of our API services.
Interestingly, the projects are being hosted at Sourceforge. I would think that google could provide their own open-source server/utilities. But as the FAQ says, the devs like SF.