GIMP

GIMP (acronym for GNU Image Manipulation Program) is a freely available, open-source raster graphics editor. Many people started using it as a replacement for a rather pricey Adobe Photoshop. Typical uses include photo editing and retouching, logo and banner authoring, resizing photos, and changing image formats. The GIMP mascot is named Wilber.

Project History
The GIMP was started by classmates Spencer Kimball and Peter Mattis in 1995 at the University of California, Berkeley. They were both members of the experimental Computing Facility, a student group at Berkeley.

Trivia
GIMP originally stood for General Image Manipulation Program but was changed after Spencer Kimball and Peter Mattis graduated from Berkeley in 1997.