(I'm the author)
it's a polyglot PDF/TeX, and you can generate the PDF by directly running PDFLaTeX on it (so you distribute the source with the viewable result)
the 2 tricks:
- include the source unmodified in the PDF itself
- modify the PDF so that it's parsed by PDFLaTeX itself.
the 2 tricks: - include the source unmodified in the PDF itself - modify the PDF so that it's parsed by PDFLaTeX itself.