i'm genuinely surprised at how well the authors of this history of the ARPAnet strike a balance between careful technical descriptions of hardware and software, useful metaphors for understanding how they work, and the personalities behind them.
every few pages, i learn something genuinely important about computing history which had direct consequences for how i work and live today.
in the computer game history world, most people recognize Will Crowther as 'that guy who created ADVENTURE' (which directly led to the entire text adventure genre).
what no one ever talks about is that before Adventure, Crowther was a chief programmer on the ARPAnet project, and designed the dynamic routing system for packet delivery. the routing software was written entirely in incredibly tight Honeywell 516 assembly, to make intelligent decisions about how to get packets from origin to destination without using a static (deterministic) routing table
a variation of this concept went into BGP, which is the very foundation of internet routing.
it's very telling that the wikipedia entry for Crowther is almost entirely about Adventure, and has almost nothing about his major contributions to the ARPAnet.