Gimp. It is an acronym for GNU Image Manipulation Program. A freely distributed program for such tasks as photo retouching, image composition and image creation. It has many capabilities.
Can be used as a simple paint program, a program for professional photo retouching, as a batch processing system online, a generator mass of images to produce an image format converter, etc.
Download Gimp user manual
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 to the procedures for handling more complex to be easily processed images tasks.
Customizable interface. Each task requires a different environment and GIMP allows us to customize the look and behavior of the way we like it.
Starting with the appearance of the program itself, which allows you to change colors, distances, widgets and sizes of icons and customize the toolbox.
The interface is modulated panels, allowing you to stack them into tabs or keep them open in its own window.
Pressing the tab key will toggle the hidden panels.
GIMP has a large full screen mode that allows you to not only preview your artwork but also do editing work while using most of your screen space.
Digital retouching: It is ideal for advanced photo retouching techniques.
Get rid of unneeded details with the clone tool, or touch up minor details easily with the new healing tool.
With the perspective clone tool, it is not difficult to clone objects with perspective in mind as easily as with the orthogonal clone.
Hardware support. Includes unique support for various input devices. Not only for pressure sensitive and tilt but also a wide range of USB or MIDI controllers tablets.
You can link actions often used to device events such as rotating a USB wheel or sliding motion of a MIDI controller.
Change the size, angle or opacity of a brush while you paint, link scripts to favorites buttons. All this translates into … accelerating workflow!