San Francisco (CA) - Facebook, the number 2 social networking site with 24 million users, is opening up to developers in its Facebook Platform program.  The company has announced that it is partnering up with 65 Internet businesses to sell ads and develop small Facebook-embedded applications called “widgets”.  Facebook will also start processing payments which will allow companies to sell items directly from Facebook.

Interestingly enough, Facebook says it will not charge partners or mandate any revenue sharing from any ads or products sold through its website, which makes this a truly open-ended development deal.  Already large companies like Amazon.com, Microsoft and Forbes have signed up.

Facebook will also let basically anyone develop small programs that could let users play ad-sponsored games or post up pictures.