[apf6]

That's a good concept but I don't think Markdown is expressive enough for all the layouts & formatting that people typically want in PDFs. More likely that the source format would be something like HTML or SVG or .docx.

[kevin_thibedeau]

Restructured text has mostly 1:1 correspondence with Docbook. I use an XSLT transform to convert its XML schema into Docbook and PDF from there via XSL-FO.