openfire http://www.igniterealtime.org/projects/openfire/ "Openfire is a real time collaboration (RTC) server licensed under the Open Source GPL. 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." Released 20100625 - Garrett Honeycutt - GPLv2