Some nerdy computer history here. And not even the exciting Bill Gates vs. Steve Jobs type stuff. Unix is surely the most influential operating system ever written. The language C is probably the most influential computer language. They were both created at AT&T Bell Labs starting around 1969 to the early 1970s, and Brian Kernighan was on the scene, involved, though not one of the primary creators.
This is largely a friendly nostalgic memoir of Bell Labs life, not the kind of hard-hitting narrative you get with the likes of "The Soul of a New Machine" (about the creation of a new minicomputer) or "Showstopper!" (about the creation of Windows NT at Microsoft). But it's in that genre of teams inventing stuff in the computer world. No unkind thing is written in this book about anyone. Most of the people mentioned and pictured in this memoir were professional adults by the late 1960s, which means of course that they are passing from this world if they haven't already done so.
Compared to other stories this was a simpler time with lower-powered machines. While Microsoft later invested years and a large harried team to create Windows NT, the first version of Unix was written in three weeks by Bell Labs researcher Ken Thompson. His colleague Kernighan (the author) was one of the first 5 or so users, and as best anyone can recall, is the one who coined the name "UNICS" (later "Unix") -- riffing on an earlier boondoggle of an OS abandoned by Bell Labs, called Multics.
Next, Kernighan's co-worker Dennis Ritchie wrote the C Language. In a key step, C was then used to re-write Unix: the early iterations were written in hardware-specific assembly language, but re-writing it in C made it more portable (that is, able to be run on various computer systems with just a bit of tweaking), and so really unlocked its growth potential. Kernighan and Ritchie then collaborated to write an iconic C programming book in 1978, "The C Programming Language", famous to this day even to a nonprogrammer like me.
Kernighan recounts a lot of micro-history of the development of many features and programs of Unix. Along the way are mentioned not only Bell employees, but also a few cameos from bright interns and graduate students who became tech-famous later: Bill Joy (cofounder of Sun Microsystems and a big name in popular tech especially about 20 years ago); and Eric Schmidt, former adult-supervision CEO of Google while Larry Page and Sergey Brin were still young and callow.
Kernighan then recounts the evolutions, variations, and open-source clones of Unix that have developed over the years. When I say Unix is influential, consider that today it exists not only as modern Unix but also as Linux, Android, MacOS, iOS, and the underlying OS in most Internet of Things devices, such as Kindle, Alexas, and in-car devices. Pretty much any operating system in wide use other than Microsoft Windows (and even Microsoft had its own version of Unix back in the 1980s, called Xenix.)
Finally, Kernighan also traces the fate of Bell Labs as AT&T and its descendents, by force and by choice, did various spinoffs and breakups and sales over the decades. Bits and pieces of it have been scattered around various industries, and veterans either retired or mostly wound up outside AT&T at places like Google. There remains however an official surviving entity even today: the modern incarnation is owned by Nokia at this point, and is called Nokia Bell Labs, website bell-labs dot com.
A good read for anyone seriously interested in computer history. Maybe not much of a page-turner for other people.