RFCs 3920-3923: XMPP!
After two-and-a-half years work, the IETF has published the XMPP specifications as RFCs. For more information see the press release from the Jabber Software Foundation. These are the actual RFCs:
RFC 3920: Extensible Messaging and Presence Protocol (XMPP): Core
RFC 3921: Extensible Messaging and Presence Protocol (XMPP): Instant Messaging and Presence
RFC 3922: Mapping the Extensible Messaging and Presence Protocol (XMPP) to Common Presence and Instant Messaging (CPIM)
RFC 3923: End-to-End Signing and Object Encryption for the Extensible Messaging and Presence Protocol (XMPP)
Congratulations to all involved in the work of the XMPP Working
Group and Jabber in general. A special mention of two people: jer,
thanks for starting this all back in 1999, and 
stpeter, thanks for all
the hard work you put into cranking out these specification!
Jabber Rocks!