The software Procreate Painter (currently at version 7) is probably the best natural media graphics software on the market, though it has minimal direct competition. Painter was initially produced at Fractal Design by the Tom Hedges, Mark Zimmer and John Derry. The team and the product later moved to the Metacreations banner, and then in 1999, Metacreations divested all its Painter interests and they were purchased by Corel, who subsequently created the Procreate banner to place them under.
Painter Classic, a stripped-down version of 5/6 was released while under the Metacreations name, and it is still distributed with Wacom graphics tablets. Painter 3D, a related product that allowed users to paint on 3-dimensional surfaces was also released, and has since been discontinued.
Despite the complicated lineage, Painter is a fairly solid product. While noted for its demands on memory and CPU, (and a UI that should have been overhauled several versions ago,) the product produces extremely natural effects which similate everything from watercolor to chalk to oil paints. It is widely used in illustration, and is more intuitive than PhotoShop. Version 7 introduced a new watercolor engine, as well as a liquid ink engine that attempts to simulate the properties of glutinous inks. Painter's extremely flexible brush engine allows users to fine-tune brushes and create their own. Version 7 migrated the brush format to XML for easy cross-platform sharing, replacing the binary BRS format.