GNU Image Manipulation Program

GIMP is an acronym for GNU Image Manipulation Program. It is
Community-driven Free Software for high-end image creation and manipulation.

It has many capabilities. It can be used as a paint program,
an expert quality photo retouching program, image composition,
an online batch processing system, a mass production image
renderer, an image format converter, etc.

GIMP is expandable and extensible. It is designed to be
augmented with plug-ins and extensions to do just about
anything. The advanced scripting interface allows everything
from the simplest task to the most complex image manipulation
procedures to be easily scripted. GIMP is available for Linux,
Microsoft Windows and macOS.