Mumble is a voice chat application for groups. It has low latency and superb voice quality. While it can be used for any kind of activity, it is primarily intended for gaming. It features an ingame overlay for DX9 and OpenGL based games, showing clearly who is talking even for fullscreen applications.
The server process (called murmur), runs on most moderns OSes. It has secure communication, and is fully controllable through D-Bus.
WinXP, Windows Vista Home Basic, Windows Vista Home Premium, Windows Vista Business, Windows Vista Enterprise, Windows Vista Ultimate, Windows Vista Home Basic x64, Windows Vista Home Premium x64, Windows Vista Business x64, Windows Vista Enterprise x64, Windows Vista Ultimate x64, Linux, Linux GPL, Linux Open Source, Mac OS X, Mac OS X 10.4, Mac OS X 10.5