miniPaint - Online graphics editing tool use HTML5 technologies like Canvas, Offline support, Drag and Drop.
Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
RealWorld Paint - RealWorld Paint is an free portable image/photo/animation editor.
Sculptris - Sculptris: Enter a world of digital art without barriers.
Paint XP for Windows 7 - Standalone old MS Paint program that allows you to get your old XP Paint interface in Windows 7.
ShapeShop - ShapeShop is an advanced and professional 3D design and modeling application that comes with an easy-to-use and user-friendly interface.