Extensible Messaging and Presence Protocol

The Extensible Messaging and Presence Protocol (XMPP) is an open Extensible Markup Language XML [XML] protocol for near-real-time messaging, presence, and request-response services. XMPP includes a method for securing the stream from tampering and eavesdropping. The XMPP network uses client/server architecture: clients do not talk directly to one another. The model is decentralized; anyone can run a server, but neither anonymous nor peer to peer, like Skype. By design, there is no central authoritative server as there is with services such as AOL Instant Messenger or Windows Live Messenger.