Well, I said I would do this a long time ago.
This package contains all of the source code from my first to my last iteration. It even contains versions I never released and an updated version that I never finished. I recommend you download the Shaunsville mega pack because the source files do not contain anything but the source, SHLT compiling tool, my own version of hammer, and the required wads.
What are you waiting for mappers? The source is here!