gimp

If you're an artist and you're looking for a program that will allow you to paint and create your artwork without any problems, then give MyPaint a try. This handy software was especially created with the painter in mind. Featuring a simple, bare bones layout and tons of brushes emulating specific types of media; the software ensures artists can easily get down to business without the hassle. It was made especially for digital painters in mind. The program is an open sourced project that's available for free download on Mac, Windows and Linux.