Cinema-MX was written to be extensible. So how do you extend it?

The actual MX architecture is described elsewhere, in a file called
"cinema-module". You will need to read this, if you want to understand
this. 

Cinema allows extension using the MX architecture. Two directories are
important for this, both within the ~/.cinema directory. Assuming that
you have installed cinema using the hard installation method, then any
jar files added into the ~/.cinema/ext directory will be added into
the classpath, so that you can access them. Secondly in the directory
~/.cinema/config directory the file "main.xml" will be loaded (if it
exists). Any other files in this directory can also be loaded using
the "load" directive, if you want to modularlise your configuration.

The final directory ~/.cinema/persist is used by Cinema to maintain
state information. 