showFoto - ShowFoto is the standalone image editor of the digiKam project.
FotoSketcher - Turn photos to paintings, drawings and sketches. FotoSketcher is a 100% free program to turn your photos into beautiful art, automatically.
PhotoDemon - Lightweight portable BSD licensed photo editor for Windows focused on performance and usability.
Elfin Photo Editor - Elfin Photo Editor is a handy program that enables you to make your photos shine.
PhotoFlare - Quick, simple but powerful Cross Platform image editor.
XnSketch - XnSketch is a handy software for Windows that allows you to modify photos and turn them into beautiful and eye-catching paintings and drawings.