GIMP is a versatile open-source image and photo-editing application available for Windows. It offers a wide array of high-quality tools for editing images and creating professional illustrations from scratch. With familiar tools like brush, pencil, clone, marker, and more, users can easily customize their brush sets to suit their preferences.

For photo retouching, GIMP provides a comprehensive set of tools including color adjustments, brightness and saturation controls, white balance, exposure settings, and much more. The program also supports features like layers, alpha channels, document history, selection tools, masks, gradients, making it easy for users to achieve professional results. Extensive tutorials on GIMP's official website further enhance user experience.