From DYOS Wiki
GIMP 2.6.7. on Windows Vista

GIMP (The GNU Image Manipulation Program) is a freeware raster graphics editor. Used to touch up images and as an editing tool. GIMP is available in a wide variety of platforms including Windows, Mac OS X, and various Linux Distros.

Use in DYOS

As an image editor, it can be used to create comics from within GIMP or from another imaging program (Microsoft Paint, Paint Shop Pro) to touch up or add in speech balloons.