Openfire has the highest feature score at jabber.org.
“Openfire (formerly Wildfire) is a real time collaboration (RTC) server dual-licensed under
the Open Source GPL and commercially.
It uses the only widely adopted open protocol for instant messaging, XMPP
(also called Jabber). Openfire is incredibly easy to setup and administer, but offers
rock-solid security and performance.”
Its one of the most amazing jabber servers out there, if you can run java on your server. It provides a plugin system, that allows you to integrate more functionality into it and they have a vivid community.
I am running it locally aswell, to test jabber implememtation for my software projects.
Give it a shot.