That IS the GIMP? But you are running OS X, I didn’t know they made the GIMP for OS X…

Yup they sure do, works like a charm!

The GIMP for OS X, Information

Now that I’ve gotten your attention, let me just say, it is very easy to get the GIMP running on OS X… It’s almost just like any OS X native app, but there is one extra step. Once completed, thats one less "extra" step you have to do again for open source applications that require the X11 windowing system to run on OS X. That step is to install X11…

• 1st download and install X11 from Apple : OS X 10.3 Download
• 2nd download and run Gimp.app (2.0.0-5) : Download
• Once you click on the Gimp.app icon it will launch the X11 windowing system, and open up Gimp. That’s it!

LINKS TO : the (compiled) Gimp.app, X11 for OS 10.2 and 10.3, and the Gimp.app source-code are all located here : http://gimp-app.sourceforge.net/

Source: Codename-Emrys.net