From http://gimp.org/

• The GIMP is the GNU Image Manipulation Program. It is a freely distributed piece of software suitable for such tasks as photo retouching, image composition and image authoring. This site contains information about downloading, installing, using, and enhancing GIMP. This site also serves as a distribution point for the latest releases, patches, plugins, and scripts. We also try to provide as much information about the GIMP community and related projects as possible.