LightZone, the RAW photo converter, can cost you hundreds of dollars for the Windows or OS X versions, however, the Linux version is free. LightZone is a powerful photo editing software package based on tonal zones with an easy intuitive interface.
The Windows and OS X versions are available in a Basic edition for $150 and a Full version for $250. The Linux version is functionally equivalent to the Full version, and did we mention, is free? LightZone is copyrighted by Light Crafts of Palo Alto, CA. They do not provide online support for the Linux version however, Anton Kast, Light Crafts’ chief architect and Linux devotee maintains a separate page to keep the Linux version updated and to provide technical support.