Murmur & Mumble
Murmur and Mumble are a VOIP suite consisting of both the server (Murmur) and the client (Mumble). They claim to have the fastest response times (lowest latencies) and best overall quality of any VOIP program currently available. On screen overlay is available for most games allowing you to see who’s connected and who’s talking without leaving your game. Mumble also supports positional audio on supported games. In supported games the locations of everyone connected are detected and broadcast appropriately via surround sound in Mumble. Your friend who is North-East of you will sound as if he is actually North-East of you. Mumble servers can often be offered at a lower cost than compared to other servers as well. For a comparison of Mumble and other voice servers check out the Voice Server Comparison page.