Lars Reichel has taken his dcpCreator front end, DCPC, and extended it with a number of features using ImageMagick. There is even a manual in English. Digital Cinema Package Creator
DCP Mastering is the technique of making a final product, such as a movie an ad or trailer, into the form that a digital cinema player and projector can handle. There are several products that do this from Dolby, Doremi and Qube, but they are not for the weak of pocketbook.
Clyde de Souza just posted an article on RealVision.ae that explains the use of some open source software at:
Free Unencrypted 3D movie DCP mastering for Digital Cinema Servers.
There are several people who have tried different variations, and have lived to tell the tale: