Matt Pagan:
Lunar:
I am still unconvinced that PDF is an interesting format for what we want to achieve.
This may not change your mind, but I wanted to point out to you that a pdf file created with wkhtmltopdf (the wk is for webkit) would preserve the interactivity of any svg files that are contained therein, (e.g. the interactive svg file you made specifically for the manual).
A PDF does not reflow its text content according to the display size. So if you have a small screen or wish bigger fonts, you have to spend all your time scrolling. It's harder to change the text colors (think about visually impaired users). I don't know about text-to-speech with wkhtmltopdf but most solutions are working fine with web browsers.
PDF are great when you print. For online uses, really, nope (unless you want the feeling of a book — but we are not doing a book).