[jshier]

Mac OS X Internals by Singh is one of my favorite books, such a great in depth examination of Mac OS X circa 10.4. I really wish there was an updated version.

Edit: I see it's even cited at the end of this article. Truly a source for the (macOS) ages.

[wpm]

Jonathan Levin’s three part series “*OS Internals” is that update, but they stopped working on and writing about Darwin around Catalina.