Source Fotoxx Homepage.
The program supports viewing of RAW camera images (NEF, CR2, etc.), as well as all other image formats, including JPG, PNG, DNG, GIF, TIFF, BMP, etc.
All in all, Fotoxx is a great photo editor for the enthusiast photographer. It can be used to do so many tasks that it may become overwhelming at some point. But it does a very good job!
The latest version is 16.02
To install Fotoxx just run the following commands via your systems Terminal.
That's all enjoy!