Wow is indeed the best way to describe this project!

From what I see, the main work horse is this 250k "binary": https://raw.github.com/manuels/pdftex.js/master/release/pdft...

This webworker script in combination with a .fmt (latex format file) generates the PDF. All in JS. @manuels__ this is awesome!

Thanks ivan_ah! I really didn't expect so much positive response!

Yes, the main work is done in the webworker (~250kb) + the tex format file latex.fmt (~700kb)