XMPP servers
ejabberd just reached 1.1.3, and you can download new fresh installers from the download page.
Of particular interest to me is the new Mac OS X Intel installer that allows me to have a ejabberd running on my Macbook.
With this, that makes three different XMPP servers now, that I run on a regular basis: ejabberd, Wildfire, and DJabberd. Each one has good and bad points. Lets see a couple of them.
Wildfire has the best admin web interface by far, and for small and medium size deployments (up to 3 or 4k online users) should work just fine. Adding plugins and most of the reconfiguring is done without service interruptions, has a decent Multi-User Chat (MUC), file transfer proxy, pubsub, and a beta gateway for other networks (MSN, Yahoo, AIM, and ICQ). All in all, pretty good package, and it's the one I use on my personal server right now. The only downsides for me are memory usage (he likes memory), and the fact that you cannot support more than one domain.
Ejabberd is the enterprise-class large scale deployment king. He keeps on working even when you throw at it indecent amounts of traffic. It has file transfer proxy, MUC, pubsub (although a bit out-of-date) and other goodies. The web interface is not the most beautiful but works and has most of what you need.
Ejabberd is also the only one of these three that can be configured as a cluster. Just add nodes and distribute your clients between them. Simple and just works.
These two are the ones you should look at first if you need a Jabber server for your company. They are actively developed and supported.
But if you like Perl and want to have fun, you can't beat DJabberd. You can easely modify any part of the server, it's all plugins, and there is still a lot to be done. There is no web interface, and only a handful of modules, but it works.
Use it if you need a very simple XMPP server or if you need to integrate with a already existing site or community.
All in all, I think that we have very mature XMPP servers out there. So, pick you poison and join the revolution.