I think you would be pretty hard pressed to design a system as functional and as clear as the Oberon System in so compact a manner that you can fit essentially all of it in one book (and implement it with a tiny team): https://people.inf.ethz.ch/wirth/ProjectOberon/index.html

I must admit I was a user of the system many years before I read the book, and I enjoyed reading the book considerably more than working with the system, but it's still a gem of a design. [Edited to fix link]