This post was expanded at 12:00 PM PT.
Facebook announced Monday that it would be making a "significant part" of its developer platform open-source. The company called it "just a first step" in a release and said that developers will see open-source technology in "most of the code that runs Facebook Platform plus implementations of many of the most-used methods and tags." Most of it is licensed under the Common Public Attribution License (CPAL) and the rest under the Mozilla Public License (MPL).
It's called Facebook Open Platform, referred to in code as "fbOpen."
The reason for going open-source, Facebook said, is that developers requested it. And it's to Facebook's advantage to listen, especially now that developers have an alternative to the Facebook Platform in the fully open-source OpenSocial.
"In helping developers better understand Facebook Platform, build tools, and share their findings, we strengthen the ecosystem as a whole and help developers build better applications," the release read. "That translates into a richer experience for Facebook users."
The social network confirmed last week, following rumors, that it would be experimenting with open-source technology.
Integrating open-source technology comes right around the one-year anniversary of Facebook's platform, which transformed the social-media world when it debuted. "It's been quite a year, with over 24,000 applications built on the platform and over 400,000 developers building new social experiences," the release from Facebook reminisced. "We see about 140 applications added to our directory per day, and nearly all of our users have added at least one application. It's been humbling for us, and incredibly exciting."