I'd love to do that, but I haven't seen any projects that have the polish and cohesive vision that I feel pro art / design tools should have. Apps like Inkscape and GIMP have always felt pretty rough around the edges and unpleasant to me, in a way that money won't help.

Can you recommend any?

i would gladly pay $500 for GIMP if i felt their developers would prioritize features that i actually need out of an image manipulation program. they never have and by the looks of things, they never will. it's too bad.

I wonder if there would be a bounty that you can set up somewhere. That would be a nice chunk to get started on a fork.