Pronounced Mac'n'Cheese, this is a very very simple shell script that uses the C preprocessor to add macros, includes, compiler errors and so forth to your JavaScript.
You can temporarily install macnjs by running this command, of course with your own path applied.
export PATH=$PATH:/path/to/the/repo
Simple:
macnjs <inputfiles> > <outputfile>
Have fun!
macnjs and all the examples are released under WTFPL.