by Rahel Lüthy
Unless you are a proud owner of a Photoshop license (or a not-so-proud owner of a PS crack), GIMP is probably your best bet when it comes to professional image editing software. It works on all platforms, the OS X version can be downloaded here.
GIMP uses a multi-window layout. On the Mac, it requires Apple’s X11 window environment (which explains, why your menu bar will say “X11” once you launch GIMP). Unfortunately, X11 has a very annoying behavior by default: If you click on an inactive window, the click will just focus that window. Say you want to select a different brush from the “Toolbox” window, this requires two clicks: One to activate the window, another to select the brush — for me, this made GIMP unusable on the Mac at first.
Luckily, I stumbled across a hidden X11 preference which does the trick:
After this is ticked, GIMP & X11 cooperate just as you would expect them to!