Yes, almost everyone knows Gimp, so i’m not going to list it here. Instead i’m only mention it here – there you have it.
MyPaint
MyPaint is not like a regular raster graphics editor, in MyPaint you have:
- unlimited canvas-size
- huge selection of brushes, and you can edit every brushsetting as you like
with version 1.0.0 MyPaint got Layermodes (not as many as the Gimp)
Fullscreenpainting without annoying dialogboxes
Krita
Krita is like the KDE equivalent of gimp. Since i don’t use Krita i can not provide you any screenshot, instead you can have a look here: Screenshots at Krita.org
Pinta
Pinta is like Paint.NET except it’s designed for Linux (yes, there is a Windowsversion too). On Mac OSX you need Mono.
Pinta has some nice filters but not as many as Gimp or Krita. You can find some Screenshots at Pinta’s website.
Alchemy
Alchemy: is a chaos generator. And really experimental – but it helps you to get new inspirations.
Take a look at David Revoy’s portfolio to see what you can do with Alchemy. Look at the Gallery on Alchemy’s website to see more work done with that tool.