Jabber Love. I've been installing and playing with Jabber since yesterday afternoon. If you don't know what Jabber is - it's an open, XML-based protocol for instant messaging and presence. So it's basically an open-source instant messaging server. It takes about 10 minutes to setup and get running, and I've installed it successfully on both Red Hat 7.3 and Windows XP. Easy as pie - that's how open source should be!