GIMP on OS X is a project, which provides pre-build  and easy to install application bundles of The GIMP for Mac OS X.
GIMP 2.6.11 is now available for Snow Leopard users. This version fixes some bugs in GIMP. For more details please read the ChangeLog. There are no other changes made to the GIMP on OS X bundles and no other plugins have been updated or changed. For a brief information about all those great and powerful plugins which are shipped preinstalled with the GIMP on OS X packages, just go to the Photo Editing page here on this site.
GIMP is the GNU Image Manipulation Program. It is a freely distributed piece of software for such tasks as photo retouching, image composition and image authoring. It works on many operating systems, in many languages. GIMP is very powerful with functionality not found in any other freeware product. It can be used as a simple paint program, an expert-quality photo-retoucher, mass production image renderer, or an image-format converter. GIMP is modular, expandable, and extensible.
Features:

• Scalable brushes.
• Improved selection tools.
• Full-screen editing.
• Improved Printing.
• Red Eye Removal. and much more…….

Customizable Interface

Each task requires a different environment and GIMP allows you to customize the view and behavior the way you like it. Starting from the widget theme, allowing you to change colors, widget spacings and icon sizes to custom tool sets in the toolbox. The interface is modulized into so called docks, allowing you to stack them into tabs or keep them open in their own window. Pressing the tab key will toggle them hidden.
GIMP features a great fullscreen mode allowing you to not only preview your artwork but also do editing work while using the most of your screen estate.

Photo Enhancement

Numerous digital photo imperfections can be easily compensated for using GIMP. Fix perspective distortion caused by lens tilt simply choosing the corrective mode in the transform tools. Eliminate lens’ barrel distortion and vignetting with a powerful filter but a simple interface.