Light Crafts is the commercial editor of LightZone, a multi-platform image editor. It supports mainly the Windows and Mac OS X platform, and it is not free: one has to pay for the software and it is not open source. LightZone integrates well into the photographer image work flow, offering a nice browsing experience and various tools to enhance zone of one’s photographs.
However, a Linux enthusiast (Anton Kast) at Light Crafts has managed to port LightZone to Linux and his company allows him to distribute this version free of charge. It is not free software, but that is still a really nice initiative from this company and its employee. Thank you Anton and Light Crafts