Presence and Instant Messaging
Presence and Instant Messaging was an early proposal to the IETF of a standard protocol for instant messaging.
The abstract model was first published as a pair of IETF Request for Comments,
No work has been done on it since 2001. Currently, SIP and its derivative SIMPLE, and XMPP are being considered for use as instant messaging protocols.
These were Informational RFCs, which describe the model and requirements for the way an Instant Messaging Protocol should work on the Internet. A new working group - the Instant Messaging and Presence Protocol group was established to develop the model in more detail.