Hello,
I'm the developer of a new MIDI performance software that makes it easier to improvise to (non-modal) chord progressions. Basically it lets you play over jazz changes (for example) by remapping the white keys to the appropriate scales in real time, though there's much more to it than that. It's not limited only to keyboards, it works with any MIDI instruments and supports ensembles. It's a free open-source project and was demoed recently at the NIME conference. Is there any interest, and if so is this the appropriate place to discuss it? I hope so!