License: Free to try
OpenFire is a real-time collaboration server based around the open Jabber XMPP protocol. It provides private and public instant messaging and group chat with support for any client that supports Jabber. Popular Jabber enabled clients include iChat, Adium, Trillium and Pidgin among many others. It’s a powerful platform for real-time collaboration with solid security and performance. There’s no easier way to get OpenFire running than to use a JumpBox.