Office LCS 2007 (Live Communications Server 2007) has a feature that’s referred to as PIC, or Public IM Connectivity. It looks like a feature that was in LCS 2005 as well, perhaps only after a service pack. It’s federation support to connect to MSN, AOL and Yahoo. I’m on Google Talk (jabber) and AOL IM (AIM) daily, so I use Pidgin (formerly GAIM) which is so much cleaner than the other IM clients, supports most IM protocols and supports a really nice tabbed messaging window.
I needed to contact a consultant that uses MSN today, and rather than install MSN Messenger and try to remember my password for it, I figured I’d setup the IM stuff.
It’s not that they reverse engineered the protocols or got a license to use the protocols or anything like that, they actually federate right into those companies networks, into the mess of it.
See Microsoft’s article about enabling PIC. Man. At the very least can’t everything support jabber? Vendor lock in for the lose.