I use GIMP on my computer, on which I run Ubuntu linux instead of Windows. I've been practicing on some of the tuts here (which are awesome, by the way!). The main problem I've run into is when I start to work on mountains and such, where the prevalent methods seem to incorporate plugins such as Felimage which, unfortunately for me, are specifically for Windows.

I was interested in finding out if anyone else does their work on linux and have found similar plugins or other workarounds for this problem. I would love to learn about these methods.