XMPP vs SIMPLE: The race for messaging standards

There’s a race on for the future of the enterprise messaging system. The contestants are backing competing protocols for IM and presence awareness. Which standard takes home the prize may depend less on technical merits than on brute force. At the head of the competition are SIMPLE (Session Initiation Protocol for Instant Messaging and Presence Leveraging Extensions) and the open-source, XML-based XMPP (eXtensible Messaging and Presence Protocol). Both are currently being developed by the Internet Engineering Task Force (IETF).

http://archive.infoworld.com/article/03/05/23/21FExmpp_1.html?standards