Facebook opens API

This is pretty huge. Facebook, the #2 social networking site in the U.S., has released an open API that allows third-party developers to "make remote procedure calls to Facebook on behalf of a Facebook user." The current version of the REST API allows applications to get information about a Facebook user's profile, friends, photos, events, messages (but of course requires said user to be authenticated). The API is free to use with a "soft" limit of 10,000 requests per day, and the Facebook Developers site currently provides PHP5 and Java client libraries, though the API could be accessed with pretty much any language.

Update: Commenter George brought to our attention Facebook Friend Mapper, a very cool Facebook/Google Maps mash-up that demonstrates what's possible with the new Facebook API. Very cool.

Tags: api, developers, facebook, open, rest, socialnetworking, socialsoftware, webservices