MetaPost + ConTeXt rendition of Oliver Byrne's "The first six books of the Elements of Euclid"
The book itself (byrne_context.tex) is licensed under CC-BY-SA 4.0. MetaPost library (byrne.mp) and lettrines generator (lettrines.mp) are licensed under GPLv3 or later.
Tested with TeXLive 2015 on Ubuntu 16.04
See releases for prepared .pdf