That's done in Photoshop, but the main thing it uses is layers and the paintbrush, so you could use GIMP or Paint.NET to do something like that.
Another Planet finally has an official release! Download chapters 1 through 3 here! Thank you for waiting so long while I kept starting over.
at 1: 49 i never noticed she had feet!
but that still leads to one problem: what drawing style am I going to use?
Well, I guess paint works.
You know, I want to grow up to become a man!
Shame I have to be jr.
(Quote from me)
Gooey goo: no, paint stinks for drawing anything. This has already been discussed.
Gootrooper: I don't understand why this would be under consideration, unless you can draw in multiple styles yourself. Just start drawing and see what it looks like; that's your drawing style.
IRC | 1.3 Patch | Reference Guide
1. Paint is a fail. Established earlier.
2. Art STYLE, not program.
3. maybe manga. that is common in graphic novels; what sort of G.N. do YOU want it to be like? mysterious? comedic?
EDIT: 4. gooey, are you talking about the medium or the program?