Openfire an easy to use IM Server

Openfire (formerly wildfire) from "Ignite Realtime" is a free and easy to install IM server based on XMPP protocol which is available for Windows, Linux and Mac platforms.
I have tried the windows version and it worked nice. Its client is named "spark" and there is a web-based client (Sparkweb) available as well.
I got to this simple and easy IM server while I was searching for a Linux client for Microsoft Live Communication Server. I have crawled a lot a of forums and after all it seems that there is no solution to that in the Linux world yet. Some posts on using Wine was available but the people who tested it didn't come out with a positive result.