What is the best Jabber server (software)? [closed]

What is the best, mature and feature rich Jabber / XMPP server?

Requirements:
- opensource (not must but preferably)
- runs under linux

Solution 1:

I've found Openfire to be quite slick and not too much hassle (it's a Java app). The Redhat package installs to /opt, which I don't think is great, whereas the Debian package is very clean and "sane", last time I checked it out.

http://www.igniterealtime.org/projects/openfire/index.jsp

Solution 2:

eJabberd is a Erlang XMPP server, its easy to install (packages exist for most major distros) and simple to admin once you get used to the config file format.

If I remember correctly, its used to run some of the larger, public jabber services out there.

If your looking for quick and simple, then as above I recommend OpenFire.