Windows Live Messenger may not be as popular as it used to be, but it's still accessed by 300 million users, and Microsoft is now hoping to grow that by making it a little more open. The service now supports XMPP and OAuth 2.0, paving the way for other chat software and services to connect more easily (some already do, but by using unofficial methods). XMPP is a messaging protocol (previously known as Jabber and used by Google Talk) and OAuth 2.0 is an open standard for authorization that both Google and Microsoft have stepped out with early support for. Maybe by opening Messenger up a bit, Microsoft is trying to avoid what happened with ICQ.