As for a good RAW image editor, take a look at Luminance HDR, RAWTherapee, UFRaw and Darktable. All are available through Software Manager.jaross wrote:GIMP is NOT a suitable substitute for Photoshop by any measure
I wouldn't go as far as to say Gimp is not a suitable substitute for Photoshop by any measure, but I would agree that most Photoshop users would find it lacking. The problem I have with Gimp is the same problem I have with PS-Elements; while both are capable programs that can do most of the things I need from PS, the toolset is incomplete and neither fit my workflow.
and I couldn't find a good RAW image editor like Photomatix either.
Here is a blog/tutorial that describes an HDR workflow using native Linux applications, and much of the work is done from the command line. All of the programs featured are available through Software Manager.