GuitarPro, in addition to the scale archive, has a scale finder feature.
You run the scale finder through a tab and it tells you which scale is the one used in the song (or the the probable matches and how many notes are out of the scale)
This is really useful then you got a catchy tune but cant get which scale you are using. That way you start writing what you like and then define which scale goes better.
Could this feature or a similar one be added to the next TuxGuitar?