I was a speaker at the TeX users meeting in Wuppertal, with the talk "Erfahrung und Vorhersagen für automatisches XML-nach-PDF-Publizieren mit TeX" (experience and prediction for automatical from-XML-to-PDF publishing using TeX).
For many years we hear the phrase "TeX can be used for XML publishing". Unfortunately, due to a few technical problems this phrase is more a desire than a fact. With my code, this desire is very near to the completion.
The most important points of the process are:
* CALS tables
These steps are the result of many tries, any xml-to-tex-to-pdf process should use them.
The slides can be downloaded here: http://www.uucode.com/download/2016/2016-dante-xmltopdf-slides.pdf. I know I need to write also a full paper to explain the content of the slides, but I can't promise it.
The current bitplant stylesheets are in github: https://github.com/olpa/tex/tree/master/bitplant_stylesheet