David A. Moon was one of the founders of Symbolics and one of the chief architects of its Lisp machines. In 1991, after he left Symbolics and joined Apple, he wrote this retrospective of Genera, "the world's first commercial object-oriented operating system": https://archive.org/details/genera-retrospective-1991
@surabax What I find interesting in this Symbolics Genera retrospective by David Moon is the discussion of the origins and motivations behind the lack of kernel protection in the Lisp Machine environment and, more generally, in Lisp. These features emerged from social dynamics and values like the opennes of hacker culture as much as from engineering design decisions.