Import Kuler palettes into GIMP 2.6.
Palettes Dock -> Menu -> Palettes Menu -> Import Kuler palette...
This plug-in requires Python. Also, make sure that the .py file is executable! If you have already installed previous version of the plug-in, you must remove the old version.
Should now correctly handle RGB and La*b* palettes. Also, basic support is there for CMYK palettes - however, the CMYK conversion is not 100% accurate. One or more of your RGB values may be 1 less than what is specified in the Kuler interface.
Tested with GIMP 2.6.1 under Ubuntu 8.04 and Win XP. Reported to work under OS X Leopard.
EDIT: please see this link for a python program that does palette conversions: