Bitmap graphics in style
Pixen is an innovative graphics editor for the Mac. It's designed from top to bottom for pixel artists—people who make low-resolution raster art like the sprites you see in old video games. But it's great for artists of all arenas: Pixen is like a very powerful MSPaint or a simpler, more agile Photoshop. Allows bitmap animation. And best of all, it's Free!
www.opensword.org/Pixen/