Pidgin 2.6.1 adds XMPP Voice and Video support

Voice and video support is only built on Jaunty (9.04) and up

Pidgin is a chat program which lets you log in to accounts on multiple chat networks simultaneously. This means that you can be chatting with friends on MSN, talking to a friend on Google Talk, and sitting in a Yahoo chat room all at the same time. Pidgin is free and contains no ads. All it's code is open source and licensed under the GNU General Public License. This means you can get Pidgin's underlying code and modify it to suit your needs, as long as you publish the changes you make for everyone to benefit from as well.

Supported chat networks:

• AIM
• Bonjour
• Gadu-Gadu
• Google Talk
• Groupwise
• ICQ
• IRC
• MSN
• MySpaceIM
• QQ
• SILC
• SIMPLE
• Sametime
• XMPP
• Yahoo!
• Zephyr