In the short term, analysts say, adoption of a common protocol will be secondary to the still-developing business models, and users and vendors will be left with multiple protocols.
AOL, MSN and Yahoo each run their services on their own proprietary protocols.
In the server space, the vendors have split into various camps. Microsoft and IBM support different implementations of a protocol based on Session Initiation Protocol (SIP), called SIP for Instant Messaging and Presence Leveraging Extensions (SIMPLE). Meanwhile the Extensible Messaging and Presence Protocol (XMPP) became a standard through the Internet Engineering Task Force, and it is largely backed in the open-source community and through enterprise IM vendor Jabber Inc.
