@bobjonkman My expectation is this book will focus on the technical details and show readers the protocol and how it can be used. I also would like a book or maybe a website which covers the story of how everything came together.
For a different protocol, SIP, they use to do what they called "bake offs" where developers would get together to try integrating their code to make sure the protocol was implemented correctly. At one point Pillsbury demanded they stop using that term. It would be fun to attend a "bake off" for ActivityPub.