[ketzu]

> 2. Even by 2016, pdfTeX had been largely superseded by LuaTeX.

Is that true? My experience was that pdftex is by far the most used one, but while thinking about it, I noticed I have zero data to back that up.

[jimhefferon]

The overwhelming majority of people writing today use pdflatex. But at this point lualatex is pretty fast, and is starting to accumlate packages that leverage it to do good things. It is starting to build momentum.