GIMP, the GNU Image Manipulation Program, has been a mainstay of free software for decades. It handles photo retouching, compositing, and digital painting with layers, masks, curves, selection tools, brushes, and a large set of filters. It reads and writes many file formats, including PSD files to a degree, and supports scripting in Python and Script-Fu for automation. The latest major version brought improvements such as non-destructive editing and better color management.
The plugin ecosystem extends it, and AI shows up there rather than as a core feature. Community plugins add background removal, upscaling, inpainting, and Stable Diffusion integration, often relying on local models or outside services. Because the program is open source, anyone can build and share such tools. Many users add G’MIC, a large filter collection, to expand what it can do.
GIMP is entirely free and runs on modest hardware. The interface can feel less polished than commercial editors, and it lacks some professional features such as full CMYK workflows, though add-ons fill part of that gap. Learning resources are plentiful. Photopea is a free browser tool that mimics Photoshop’s layout, Krita is a free app focused on painting and illustration, Affinity Photo is a low-cost one-time purchase, and Photoshop remains the industry standard for professional work.