Why does Brian Kernighan think the C programming language succeeded?

Brian Kernighan said C hit a sweet spot between efficiency and expressiveness. Around 1972 the first machine it ran on had about 24K bytes of memory and a half-megabyte disk, so the language had to be small enough that a programmer could see how it translated into PDP-11 instructions and a compiler was easy to build, while still letting people say what they needed. Features like runtime checking were left out to save memory, and since C was built to write an operating system it skipped what that job did not need. Unix and C then reinforced each other.

• Kernighan said Unix was easier, more productive and more fun than commercial operating systems of the time, so people adopted it and wrote tools in C.
• Kernighan said other languages are now better choices for many purposes, but C keeps its efficiency and expressiveness.

▸In their words

“i think it hit a sweet spot in some sense of like efficiency and expressiveness” Brian Kernighan · at 39:48 — open in the transcript →

Source: our own transcription of the episode. The full conversation is on Ryan Peterman (2026-10-26). Read the whole episode summary →

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