" While virtually all computer graphics professionals use Adobe
Photoshop to do their artistic work, Photoshop is a pricey and
proprietary application. If you're looking to do graphics design on
a budget, or perhaps want a software package that is less
resource-intensive than Photoshop, check out open source
alternatives--the GIMP, SodiPodi, and Inkscape.
"For working with raster images, photographs, and the like, the
open source king is the GNU Image Manipulation Program, better
known as the GIMP. Most Linux distributions come with the GIMP in
the standard install. The latest version is GIMP 2.0..."