Anyone know if Ardour can be used commercially?

I've been looking for good free Digital Audio Workstations (DAW's) on either Windows or Linux. The main requirement is that I can make music with it, and then sell that music without any worries. It also needs to be able to use VST's. There are some free programs/demo versions of DAW's going about. But a lot of them don't allow you to sell the music you make. I even have Ableton 8 Lite which I got through a Soundcloud promo. But I don't know if you can sell music made with that. Not actually sure... So anyway, Ardour is what I want to have a go with. I can't find anything about the licence. Anyone know? Also if you know the deal with Ableton Lite or have any other program suggestions then please let me know :) Thanks.