This is a fantastic idea, reading the self-documenting code right now. This is like a cross between literate programming and a C preprocessor, with a sprinkle of build management.
I can picture a few powerful ways of using this. Thanks for sharing!
It also uses markdown and its code conventions.
It is still early stages, but it seems to be working fine. It compiles itself, of course.
It has the ability to compile snippets mid-compiling. So one probably could, for instance, write small self-contaied snippets of coffeescript and potentially merge the compiled version into a normal javascript script, all of which is being compiled from a single (or multiple if you like) markdown documents.