GrafX2 is a bitmap paint program inspired by the Amiga programs Deluxe Paint and Brilliance.
Specialized in 256-color drawing, it includes a very large number of
tools and effects that make it particularly suitable for pixel art, game
graphics, and generally any detailed graphics painted with a mouse. The
program is mostly developed on Linux and Windows, but is also portable
on many other platforms.
Grab here (RTG)