Today, Lead Program Manager over in the Messenger camp, Dare Obasanjo, wrote about enabling public access to the Messenger network via… yep, XMPP. (The Windows client’s days are numbered.)
Today we’re taking another step, with the public availability of access to the Messenger network via XMPP, an open standard. This means that anyone can build innovative messaging clients—either stand-alone or built into their devices—that include access to Messenger’s 300 million active users. […]
Developers interested in learning more about our XMPP interface can check out our code samples on GitHub along with the overview documentation on the Live Connect developer center. These should give you enough information to get started building integration with the Messenger network into your mobile apps, devices and web sites.
There are still some missing basics though, like the ability to add/remove folks from your buddy list. Maybe in a future release.