Section 2 of the article, on Justified Layout, was a joy to read. As it says, it's inspired by (adapted/simplified from) TeX's line-breaking algorithm, described by Knuth and Plass (http://www.eprg.org/G53DOC/pdfs/knuth-plass-breaking.pdf). The paper is a fantastic read. Even if you never use TeX, it's worth reading. (I elaborated more on it here: https://tex.stackexchange.com/a/423578/48)
As reading the paper will make clear, it's really incredible how with very simple primitives (boxes, glue and penalties), we can achieve so many different kinds of layout. Sometimes when I'm struggling with CSS layout I yearn for a layout model as simple as TeX's. (Though of course CSS has other hard problems to solve like variable width and "simpler" users, and I guess the most recent additions to CSS, like Flexbox and Grid typesetting, are some small steps in the direction of approaching the power of TeX circa 1978.)
As reading the paper will make clear, it's really incredible how with very simple primitives (boxes, glue and penalties), we can achieve so many different kinds of layout. Sometimes when I'm struggling with CSS layout I yearn for a layout model as simple as TeX's. (Though of course CSS has other hard problems to solve like variable width and "simpler" users, and I guess the most recent additions to CSS, like Flexbox and Grid typesetting, are some small steps in the direction of approaching the power of TeX circa 1978.)