MJS:
Exchange 2000 did have an IM component. It was pretty easy to implement and
utilize. However, this feature was removed out of Exchange 2003.
Exchange's IM relied upon a Microsoft-centric protocol called RVP.
Microsoft has replaced this with Microsoft Office Live Communications
Server, which relies on the industry recognized standard of SIP, or Session
Initiation Protocol (you may also hear SIMPLE). The current version is LCS
2005. More information regarding this product is available at
http://office.microsoft.com/livecomm
If you decide on LCS, you may want to take some time to read the newsgroup
microsoft.public.livecomm.general and possibly look at the archives on
Google Groups. Both of the LiveComm newsgroups (general and developer) are
out there. This is a great newsgroup with some really helpful people. We
have an active MVP as well as several active MSFT folks. There are also
some really wonderful folks in the group, several who have turned from
asking questions to both asking and answering.
Bob