Pixelitor - Pixelitor is a cross-platform raster graphics editor written in Java.
PhotoDemon - Lightweight portable BSD licensed photo editor for Windows focused on performance and usability.
FastStone Image Viewer - FastStone Image Viewer is a fast, stable, user-friendly image browser, converter and editor.
PixBuilder - Free Photo Editing Software for PC
GIMP - GIMP is a multiplatform photo manipulation tool.
PhotoFlare - Quick, simple but powerful Cross Platform image editor.