SpeedyPainter!

Krita is a complete creative sketching and painting application with advanced, commercial quality features. It's free, open-source and available across all major desktop platforms.

MyPaint is a fast painting program with an emphasis on full-screen use. It lets you focus on the art instead of the program. You work on your canvas with minimum distractions, bringing up the interface only when you need it. MyPaint supports pressure or tilt sensitive graphic tablets and comes with an easy-to-use brush collection. There is a complex interface for creating own brushes, focusing on brush dynamics (changes with speed, pressure, randomly).

Enter a world of infinite creativity with the comprehensive photo-editing and graphic design power of PaintShop Pro X8. Accelerate your photo editing with enhanced layers, more precise selection tools, faster brushes and extensive productivity-boosting improvements. Bring ideas to life with the most versatile photo-editing software value anywhere.

Corel Painter is a raster-based digital art application created to simulate as accurately as possible the appearance and behavior of traditional media associated with drawing, painting, and printmaking. It is intended to be used in real-time by professional digital artists as a functional creative tool.

Sumo Paint is a powerful image editor with a long-standing history as a fully capable Photoshop clone in the browser. Being designed for the browser, it's accessible on practically any system and loads much faster than most comparable desktop tools while still providing core commercial features like layer-based editing with layer effects, multiple built-in filter effects and color adjustment tools.

A simple but lovely natural media painting and sketching program. Art oriented, but capable of loading/saving photoshop files. A very cheap alternative to Painter, with a stripped down, elegant interface.

Verve (Dictionary: Energy and enthusiasm in the expression of ideas, especially in artistic performance or composition...) is the result of a curious idea I had to try using the graphics hardware to run a fluid dynamics simulation. Despite some little flaws, as you may observe at faster motions, it works astonishingly well across rather large resolutions. This permits highly detailed simulations of all kinds of liquids, and it screamed to be used for painting.

Alchemy is an open drawing project aimed at exploring how we can sketch, draw, and create on computers in new ways. Alchemy isn’t software for creating finished artwork, but rather a sketching environment that focuses on the absolute initial stage of the creation process. Experimental in nature, Alchemy lets you brainstorm visually to explore an expanded range of ideas and possibilities in a serendipitous way.

Webchemy is an open-source cross-platform web-app for creating idea sparking sketches. Based on the desktop application Alchemy, Webchemy takes some of its drawing tools and brings them to the web. Webchemy is great for generating new ideas, but at some point it's better to take your concepts and let them evolve within other tools. That's why you can export your creations as PNG and SVG (Scalable Vector Graphics).

TwistedBrush is a digital paint software and photo editor that supplies a wide variety of natural art tools.

Project Dogwaffle lets you be creative without the fear of mom or wifey yelling at you because you messed up your clothes again. No sudden spills, no funny fumes. You can paint, erase it, and try again, and again, and again......