Back in 2002/2003, for reasons I can't explain, I decided to re-typeset the classic Don D. Worth / Pieter M. Lechner book, "Beneath Apple ProDOS". This is is the LyX project for that. I don't recall what state it was in when I left it, but many of the tables are incomplete or missing and all of the graphics are missing. In the releases tab there's a PDF version (created with LyX 2.2).
(Beneath Apple ProDOS was reclassified as freeware in 2002).