Pixen

Pixen is an open-source raster graphics editor created by the Open Sword group. It is designed to create and edit pixel art. It runs on Mac OS X. The latest version is Pixen 3.

Pixen utilizes a basic interface similar to that of Adobe Photoshop. While common tools are included in Pixen, such as the pencil, eraser, and fill tool, Pixen also uses a unique left/right tool system. This system enables the user to assign a different tool to the left and right mouse buttons. This can be used effectively when drawing and erasing. It also features several color palettes, as well as integration with Mac OS X's color options.

Unlike most basic bitmap-based applications like Microsoft Paint, Pixen has a layer system that will let you organize parts of an image, name them, or hide them. Again, some of its tools can be compared to Photoshop. The magic wand tool is one that is particularly notable.