It came free with my Behringer mixing desk. I haven't gone too far with it yet. It was a bit annoying that you get version 4 free with the brand new desk when version 6 is the latest on their web site. The interface looks a little scrappy in Windows, probably because it does its own anti-aliasing, so no cleartype. (Probably using some ported linux GUI lib). Will report back after using it for a while.