GIMP (/ɡɪmp/ GHIMP; GNU Image Manipulation Program) is a free and open-source raster graphics editor used for image manipulation (retouching) and image editing, free-form drawing, transcoding between different image file formats, and more specialized tasks.
GIMP is released under GPL-3.0-or-later license and is available for Linux, macOS, and Microsoft Windows
GIMP is primarily developed by volunteers as a free and open source software project associated with both the GNU and GNOME projects. Development takes place in a public git source code repository,[on public mailing lists and in public chat channels on the GIMPNET IRC network.
New features are held in public separate source code branches and merged into the main (or development) branch when the GIMP team is sure they won't damage existing functions. Sometimes this means that features that appear complete do not get merged or take months or years before they become available in GIMP.
GIMP itself is released as source code. After a source code release, installers and packages are made for different operating systems by parties who might not be in contact with the maintainers of GIMP.
The version number used in GIMP is expressed in a major-minor-micro format, with each number carrying a specific meaning: the first (major) number is incremented only for major developments (and is currently 2). The second (minor) number is incremented with each release of new features, with odd numbers reserved for in-progress development versions and even numbers assigned to stable releases; the third (micro) number is incremented before and after each release (resulting in even numbers for releases, and odd numbers for development snapshots) with any bug fixes subsequently applied and released for a stable version.
Download GIMP: https://www.gimp.org/downloads/