RawTherapee is a cross-platform raw image processing program, released under the GNU General Public License Version 3.

ImageOptim makes images load faster. Removes bloated metadata. Saves disk space & bandwidth by compressing images without losing quality.

PhotoBulk is an easy-to-use batch photo editor. Watermark photos, Optimize and Rename photos at once.

OptiPNG is a PNG optimizer that recompresses image files to a smaller size, without losing any information.