This addon will work with Blender CAM installation or any blander which has Numpy library built-in. Best way to use it is to download blender CAM, unpack it, then follow the tutorial.
The bas-relief addon will be sent to all donors of Blender CAM as a bonus. Even if you donate a single euro(-cent), you are eligible to recieve a link to this addon. When the donations to BlenderCAM reach 2000 Euro since the moment of release of the basrelief addon(November 2013), the basrelief addon will be opensourced under the GPL license, and the documentation and tutorial published online. It will be then distributed with Blender CAM. If the donations keep the rate which they had until now, this will happen approximately in 3.5 years :)
UPDATE: the limit has been reached, thanks to everybody! You can still donate if you like whatever you use from this site ;)