miniPaint - Online graphics editing tool use HTML5 technologies like Canvas, Offline support, Drag and Drop.
PhotoDemon - Lightweight portable BSD licensed photo editor for Windows focused on performance and usability.
RealWorld Paint - RealWorld Paint is an free portable image/photo/animation editor.
PixBuilder - Free Photo Editing Software for PC
Paint XP for Windows 7 - Standalone old MS Paint program that allows you to get your old XP Paint interface in Windows 7.
showFoto - ShowFoto is the standalone image editor of the digiKam project.