Teamspeak

TeamSpeak

http://www.goteamspeak.com

TeamSpeak is an application which allows its users to talk to each other over the internet and basically was designed to run in the background of online games. The voice quality and hereby the bandwidth usage is configurable and can be low for modem users or as good as normal phone calls for better connections. Still the client’s maximum bandwidth won’t exceed 25.9 KBit/s (=3.3 KB/s) upstream.
Also TeamSpeak uses as little latency as possible, which makes TeamSpeak one of the best online gaming communication programs.

But one of TeamSpeak’s largest advantages is: TeamSpeak is a cross-platform voice communication tool. This means that client and server are available for Windows as well as for Linux.

Additionally we have to say that TeamSpeak is a contribution to the gaming community and thus it is completely free for non-commercial users.

See also: Ventrilo