eXtensible Messaging and Presence Protocol ([XMPP](http://www.xmpp.org/))

(formerly known as [Jabber](http://www.jabber.org/)) is an open, XML-inspired

protocol for near real time, extensible instant messaging (IM) and presence

information (a.k.a. buddy lists). The protocol is built to be extensible and

other features such as Voice over IP and file transfer signaling have been

added.

* [XMPP Protocol](http://www.xmpp.org/protocols/)

* [XMPP Extensions](http://www.xmpp.org/extensions/)

* [Wikipedia](http://en.wikipedia.org/wiki/Extensible_Messaging_and_Presence_Protocol)

* [XMPP About](http://www.xmpp.org/about/)