[PhilD]

It all depends on what you start from. The basis terrain can be created by this Fractal Terrains program; then you need software to convert the file to TGA format, and make sure there are no "pure white" dots other than the province capitals.

Adding province borders is optional, though it's certainly a good idea; any image manipulation program should let you do that.

Then you need to do the tough work: make up the province connectivity, and decide on the terrain of each province. The dom2 editor is the only visual tool for that; doing this with a simple text editor is certainly possible, though it's not exactly easy since it's so hard to find out about the province numbers. Mixing the two should be possible.