I did some development with Linux back in the late 90s, not a pleasant experience. But I think John has nailed it with the view towards drivers. I'm sure there are some out there but why would you want to go down that path?
At this point, it seems, Linux is starting to suffer from the same problems that plagued the various flavors of Unix, your code might compile on your version of Unix but it wouldn't run on any other vendors...I seem to recall Unix flavors by IBM, SUN, HP, DEC and all the other large players in enterprise development work.
It is kind of interesting that there is a new DAW on the market though, nice to see some more competition, particularly if it leads to more innovation across the playing field.
Regards,