Is it legal to improve the source code and, after, sell the program on third-party sites?.Though a photo editor GIMP is free, it doesn’t impose any restrictions on the type of work you can do in it. Can I use GIMP for commercial purposes?.Yes, this photo enhancer supports almost all file formats, including RAW, TIF, GIF, PNG and many others. Professional tools for photo retouching.This photo editing software has an open source, which makes it completely free. GIMP is called the best free alternative to Adobe Photoshop, and you have probably heard about GIMP vs Photoshop competition. Download GIMP free and start using this image manipulation software on any platform you use: will it be Mac OS, Windows or Linux.