Just a few short years ago it looked as though XMPP, the XML-based messaging protocol central to the Jabber IM platform, was fading away. Microsoft had committed to the SIP-derived SIMPLE (SIP Instant Messaging and Presence Leveraging Extensions) for its Live Communications Server IM platform, while iBM Lotus incorporated SIMPLE as the basis for Sametime. The momentum behind unified communications around 2006 appeared to leave XMPP in the dust, as vendors rapidly looked to SIP and SIMPLE as the basis for integration of presence with rich-media applications such as voice and video. But then a funny thing happened....
XMPP's fortunes turned around rather quickly in the last three years, first with Google's decision to focus on XMPP as the basis of its Gtalk instant messaging platform, even working with XMPP standards groups on a XMPP derivative known as Jingle to support voice and video. Then Cisco gobbled up Jabber Inc., the commercial firm delivering enterprise-class XMPP platforms. (While there continues to be a lot of confusion around Jabber and XMPP, it's important to remember that XMPP is a protocol, while Jabber.org is an open-source IM service, and Jabber Inc. was a private company delivering XMPP-based enterprise IM platforms.)
XMPP continues to gain momentum, with Google Wave using XMPP as its messaging protocol (extending it through the Google Wave Federation Protocol). Now, through its Jabber acquisition, Cisco has embraced XMPP as the basis for its presence federation services (Cisco Unified Presence) as well as instant messaging services delivered either on-premises through Cisco Unified Personal Communicator 8.0, or Cisco WebEx Connect Instant Messaging, supporting any XMPP-capable client application such as Pidgin or Adium. Previously Avaya had announced support for XMPP as well, both to federate with Google Apps, as well as to support federation with XMPP services through its Aura Presence Services.
While SIP continues as the dominant protocol for voice and video, it's clear now that XMPP has gained a new lease on life. Will we see a change in direction away from SIMPLE for Microsoft and IBM?