Pixel (formerly Pixel32) is an image editing program, similar to Photoshop or Gimp, that runs on a large variety of platforms: Linux, FreeBSD, Zeta, OS X, SkyOS and more. In an 8 year period, it has grown to become a very pleasant-looking and usefull application. It currently supports a large variety of formats, and though it is not open-source, we consider it to be a must-have for every Linux user. Unlike Gimp, it has support for CMYK and uses it's own GUI toolkit called eLiquid. Pixel can work with PSD files and work is being done to improve this feature.
The following is an interview with the developer.
http://www.linuxinterviews.com/index.php?option=com_content&task=view&id=14&Itemid=2