Awesome
Export / reimport (and Gimp) lua script for Darktable 2.x
This script is a simple hack to export and reimport the image in a roll.
After reimport, you can open the image with gimp.
Alternatively, you can open directly in gimp (configuring a shotcut in the preferences)
Pay attention to this page, before open images in gimp.
Tested with darktable 2.0