Someone in IRC mentioned that this is like a mumble clone, so then they asked why not just use mumble?
I'm not sure if it is functionally the same (or the same in terms of quality), but it could be easier to integrate into Nexuiz than Mumble. From what I understood from Div, the mumble code was a bit complicated to integrate because of how they chose to design the software.
Also, I know of one person (mkzelda) that experienced serious lag during gameplay when someone would speak using mumble. Perhaps this program uses more efficient methods/codecs.