How Ken Thompson built the digital world

The text on your screen, the operating system running your phone, and the security protocols protecting your bank tab share architectural DNA. Most of it was laid down by a man who started by trying to play a bootleg video game about space travel. This episode is a deep dive into Ken Thompson, the Bell Labs engineer whose curiosity quietly built the modern digital world.

We trace the path: the Berkeley education, the side project that produced Space Travel and forced him to look for unused machines, the discovery of a PDP-7 that became the launchpad for Unix, and the philosophy that emerged with Dennis Ritchie of writing software as small composable tools that do one thing well. We unpack the inventions: the B language that would become C, regular expressions, the QED and ed editors, the early grep, and the surprising side adventure of Belle, the chess machine that won a world computer chess championship.

We also cover his Turing Award lecture "Reflections on Trusting Trust," the haunting demonstration that you can plant a backdoor inside a compiler that even a clean source code review will miss, and his more recent collaboration with Rob Pike and Robert Griesemer on the Go programming language. Then we cover UTF-8, the elegant 1992 design (one paper napkin, one diner) that solved the encoding mess for the entire global internet. The episode closes with the question Trusting Trust forces: do we now have any choice but to believe a few decades-old codebases on faith?

Subscribe to pplpod for more deep dives into the people who built the modern world. Topics: Ken Thompson, Unix, B language, Bell Labs, Plan 9, Go programming language, UTF-8, Trusting Trust, Turing Award, computer science history.

Source credit: Research for this episode included Wikipedia articles accessed 5/3/2026. Wikipedia text is licensed under CC BY-SA 4.0; content here is summarized/adapted in original wording for commentary and educational use.