What is fun is the Switcher/Multi-Mac debacle. Notice that it was mentioned that "I knew that releasing it would have me having to keep up with all the new ROM releases from Apple in the future." At the time, even with the 128K ROM I think they still had to put special code to support Switcher into there (Andy was also working on the Font Manager at the time).
Great story. What jumped at me was Andy's reaction to Steve's 100K offer. Mine was to counter with "I already have one client lined up, and their lawyers will be happy to deal with any 'confidential information' issues". I suspect mere mention of Microsoft would make Jobs mad and at least double the offer.
You may know, but for readers who don’t: ”they” didn’t, Andy Hertzfeld did (https://www.folklore.org/StoryView.py?story=Switcher.txt)
It helped that he had intimate knowledge of the Mac operating system’s internals, but many of them were documented in Inside Macintosh, and others could have been found with (quite) a bit of effort; one didn’t have to be at Apple or even have access to the system’s source code to implement that.
And those volumes aren’t useless; they are reminders of about the last time hacking an OS was fun :-;