Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
Photoscape - high quality photo editing software, that enables you to fix and enhance photos.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Pixelmator - Pixelmator is an image-editing application for Mac and iPad.
Cinema 4D - Cinema 4D is a 3D modeling, animation, motion graphics and rendering application.
Pixlr - Pixlr® makes it easy to transform everyday images into stunning works of art.