I wouldn't say Kerodon is collaborative, but why the $n$Lab isn't in the list?

Personally, I would mention two books:

Kennington's "Differential geometry reconstructed" http://www.geometry.org/tex/conc/dgstats.php the author develops everything in great detail from the start, and by "the start" I mean his personal views on metamathematics, predicate logic, sequent calculus, algebra, analysis, and all the topology you'll ever see/need.

The last release of "Foundations of almost ring theory" https://arxiv.org/abs/math/0409584 where the authors take personally the absence of a comprehensive textbook on 2-category theory.