TeamSpeex is an unsupported, unofficial 3rd party TeamSpeak 2 client application for the Mac, that is in no way affiliated with TeamSpeak Systems.

It's named TeamSpeex because it only supports the Speex codec. Since no one of us owns a Mac, we've not tested the functionality of TeamSpeex, but accoirding to its users, it is fully compatible with existing TeamSpeak 2 servers, and with PC and Linux users.