XMPP POWERS A WIDE RANGE OF APPLICATIONS including instant messaging, multi-user chat, voice and video conferencing, collaborative spaces, real-time gaming, data synchronization, and even search. Although XMPP started its life as an open, standardized alternative to proprietary instant messaging systems like ICQ and AOL Instant Messenger, it has matured into an extremely robust protocol for all kinds of exciting creations.
Facebook uses XMPP technology as part of its chat system. Google uses XMPP to power Google Talk and its exciting new Google Wave protocol. Collecta has built a real-time search engine based extensively on XMPP's publish-subscribe system. Several web browsers are experimenting with XMPP as the basis of their synchronization and sharing systems. Dozens of other companies have XMPP-enabled their web applications to provide enhanced user experiences and real-time interaction.
The core of XMPP is the exchange of small, structured chunks of information. Like HTTP, XMPP is a client-server protocol, but it differs from HTTP by allowing either side to send data to the other asynchronously. XMPP connections are long lived, and data is pushed instead of pulled.