TwistedBrush is a complete utility for artists with a simple to use and intuitive interface. Comes with artistic brushes, layers, realistic media, photo cloning, tracing, masks, particles, filters, script recording, and scripts to AVI. The program supports drawing tablets, patterns, textures, Adobe compatible plug-in support, integrated scanner support, drawing guides, reference image views, dirty brushes, scratch layer, dynamic palettes and a whole lot more.

The free edition of TwistedBrush with most of the great features of the commercial version apart from brush editing and fewer included brushes. The program comes with a tutorial that appears at startup, which is recommended.

NOTE: the website no longer mentions this free version -- linking to Softpedia (thanks billon).