Making Fractal lines in GIMP, Photoshop, or PaintNET
I'm looking for some sort of tool for GIMP, Photoshop, or PaintNET (that last one is unlikely) that will allow me to make a randomized line or perhaps even a randomized shape that looks like topography. I created a map in Fractal Mapper 8 (seen here) that utilizes these sorts of tools which was great for my concept, but actually making it look pretty is something the program is not very good at.
Ideally I want to make the borders glow (like this) as well, but I'm also going to need to put rivers on the map as well as make other modifications. I took a look at the GIMP tutorials, but none of them mentioned a randomized line tool like what I need.