Cinepaint

"Top Reasons to Use CinePaint

1. Support for 8-bit, 16-bit and 32-bit color channels of deep paint.
2. High fidelity image file types such as DPX, OpenEXR and 16-bit TIFF. These files can't be opened in ordinary 8-bit image applications (e.g., GIMP) without crushing them.
3. High Dynamic Range. HDR images can go brighter than white. Ordinary images can't be brighter than a white sheet of paper (0=black, 1.0=white).
4. Gallery-quality printing. B&W photographs have only one color channel and degrade quickly when manipulated as 8-bit images. CinePaint has higher fidelity and offers a 16-bit printing path to the print-head using GutenPrint.
5. Color Management System. CinePaint uses LittleCMS.
6. Flipbook. Movie playback of short sequences of images in RAM.
7. Innovation. CinePaint offers features that go beyond ordinary painting tools.
8. It's used to make feature films at major studios.
9. Open Source. With various OSS licenses, because it uses code from various sources, including GPL, LGPL, BSD, and MPL.
10. Free.
11. Friendly professional developers. Polite discussion forums.
12. Being a CinePaint developer can be a good career move. CinePaint developers have gotten jobs at companies such as DreamWorks Animation, Sony Pictures Imageworks, and Apple. "

http://www.cinepaint.org/