Low-latency, high-quality voice communication for gamers. Includes game linking, so voice from other players comes from the direction of their characters, and has echo cancellation so the sound from your loudspeakers won't be audible to other players.
Mumble, the low-latency VoIP application for games, has just released version 1.1.5 for Windows, Linux and Mac OS X. The files can be downloaded from https://sourceforge.net/project/showfiles.php?group_id=147372.
Along with lots of bugfixes, this release adds support for controlling Murmur through ZeroC ICE, and key suppression, so your Mumble shortcuts won't affect your game.