PUB was an early markup language developed by Les Earnest in 1971 at Stanford AI Lab. It aimed to create paginated documents for programmers using the PDP-10 system. Despite its quirks, PUB gained popularity among Ph.D. candidates for formatting dissertations. It inspired the development of Scribe and TeX by Brian Reid and Don Knuth. PUB’s reinventions, JavaScript and PHP, have become vital in web authoring. The manual, reproduced in 1972, showcases its capabilities like cross-references, page numbering, and macros. PUB paved the way for generalized markup languages like GML and SGML, influencing the development of HTML and XML.
https://www.nomodes.com/history/pub-manual