GIMP (/ɡɪmp/; an acronym for GNU Image Manipulation Program) is a free and open-source raster graphics editor used for image retouching and editing, free-form drawing, resizing, cropping, photo-montages, converting between different image formats, and more specialized tasks.

GIMP began in 1995 as the school project of two university students; now GIMP is a full-fledged application, available on all distributions of Linux, OS X and Microsoft Windows — XP and later versions.It is released under GPLv3+ licenses and is freely distributed to (and by) anybody, who can look at its contents and its source code and can add features or fix problems.

GIMP is expandable and extensible; it is designed to be augmented with plug-ins and extensions in order to improve its functionality. This is implemented through the use of a scripting interface.