I used to use Teamspeak and Ventrilo a lot and even ran a server. Mumble is a good open source alternative. Too bad it's hosted on SourceForge. These guys look

I used to use Teamspeak and Ventrilo a lot and even ran a server. Mumble is a good open source alternative. Too bad it's hosted on SourceForge. These guys look like they're using the same sort of tech to help remote working teams: http://speak.io/ http://speak.io/