Dennis Ritchie

Dennis Ritchie joined Bell Labs in 1967, where his father had worked for decades. He was assigned to Multics, an ambitious operating system built jointly with MIT and General Electric that was late, expensive and eventually abandoned by Bell. What was left was a handful of programmers who had liked working on it and no longer had a machine.

Ken Thompson found an unused PDP-7 minicomputer and, in 1969, wrote a small operating system on it so he could keep playing a space travel game. Ritchie joined him, and what began as a hobby became Unix. Its ideas, that everything is a file, that small programs should be chained together, that the system should be simple enough to understand, were new at the time.

Between 1969 and 1973 Ritchie designed the language C to write it in. Until then operating systems were written in assembly language tied to one machine. Rewriting Unix in C meant it could be moved to almost any computer, and that decision is why it spread. The book he wrote with Brian Kernighan in 1978 is still in print and its terse style shaped how programmers write.

He was modest, wry and never sought publicity. Linux, Android, macOS, iOS and most of the internet's servers descend directly from his work. He died at home in October 2011, a week after Steve Jobs, and the news was barely noticed.