Have you seen How To Create A PDF From Your Web Application by Rachel Andrew? It's a good overview and an awesome additional reading for people interested in the topic.
Mostly Paged.js seems really interesting to me as a polyfill to give print CSS some well deserved love.
Also I'm mostly interested in ebook (pdf/epub) at the moment but still curious. Seems like you got the dead tree version made through leanpub? How was your experience using it? How were the formats (they seem to be using a custom markdown flavour?)? Was styling for the printed version hard/different compared to the pdf/epub version?
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.