This free software helps you installing quickly shaders for Mental Ray under Maya.
Once configured, you have to give the path of your shader and link and mi lines and that's all. ShaderCopy copies files where they should be and changes you maya.rayrc file!!
ShaderCopy is available in English and in French. It was developped with Qt OpenSource so it is opensouce. You can find sources on http://www.devic.net
To make it work with Mac and Linux, you should have Qt installed (version4) and compile sources! Unzip the sources. Once unzipped, in the root directory of ShaderCOpy type "qmake<return> make<return>"