Gimpshop - Gimpshop is a modified version of The Gimp (the GNU Image Manipulation Program), that offers a more Photoshop like layout. Gimpshop was created by Attack of the Show’s Scott Moschella.
Photoshop:

Gimpshop:

Gimpshop is available to all major Operating Systems (Mac, PC Windows, Linux…). To get gimpshop, head over to the project’s page on freshmeat.net for the latest builds, or you can build it from source, get it from Scott’s page (linked above).
Gimpshop Review [PCMag.com]
Gimpshop Review [About.com]
