PhotoFlare - Quick, simple but powerful Cross Platform image editor.
FotoSketcher - Turn photos to paintings, drawings and sketches. FotoSketcher is a 100% free program to turn your photos into beautiful art, automatically.
showFoto - ShowFoto is the standalone image editor of the digiKam project.
Magic Photo Editor - Magic Photo Editor for Windows is a feature-rich application that allows you to create original edits of photos.
PhotoDemon - Lightweight portable BSD licensed photo editor for Windows focused on performance and usability.
FaceFilter Studio - Everyone takes poor photos, now...