I started on the map with just Gimp then someone mentioned Wilbur for height maps and, so I used that to help with the land texturing and with the plateaus. So that's it, just Gimp and Wilbur.

Overall I am fairly pleased with how the map turned out. After playing with Wilbur I think I could do the mountains a lot better. The coastline is pixelated because of a filtering mistake .. I was doing a lot of experimenting. Hopefully, I still have a pristine layer of the coastline somewhere but, the number of saves and the number of layers started to get me confused... we'll see if I can find it.