GIMP – which stands for the GNU Image Manipulation Program – is a feature-packed and powerful open source image editor that can be used in all major operating systems (Linux, Mac, and Windows). It has a customizable interface so that you can easily set the view and behavior of GIMP.
It has a huge set of retouching tools that will allow you to perform advanced image retouching and manipulation. The GIMP outputs your work in many common formats like JPG, GIF, PNG, TIFF, and even PSD (Photoshop’s native file format).
