Jabbers and others important

Jabber servers:

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

JabberIn
http://www.jabbin.com/index.html

OpenZoep: An Open Source VoIP Engine

http://www.voipster.com/

VOIP Jingle library
http://www.xmpp.org/extensions/xep-0166.html

XPCOM
http://www.mozilla.org/projects/xpcom/

http://xmpppy.sourceforge.net/