Ken Thompson, inventor of UNIX

Kenneth Thompson was born in 1943 in New Orleans, Lousiana. He got his MS degree in Electrical Engineering from Berkeley in 1966. Shortly after graduating, Ken Thompson joined the Bell Labs Computing Research Department.

When Ken Thompson began working at Bell Labs, he was a programmer for the Multics operating system. The project ultimately disbanded, but Ken Thompson was intrigued by several interesting ideas from Multics, and began experimenting on them on a PDP-7.

Ken soon got the help of Dennis Ritchie, and in 1969, the first UNIX system was born. Ken Thompson also created the B language, precursor to C. By 1973, Ken Thompson and Dennis Ritchie rewrote UNIX in C, making it the first truly cross-platform operating system.

There are many reasons why UNIX is a very popular operating system, and has endured over these many years. One reason surely is that AT&T was legally bound to not profit on the software, and chose to give the source code of UNIX for free to universities across the United States.

But ultimately, I believe it is the simplicity of its design that has made UNIX attractive to computer scientists around the world. In a Computer Magazine interview, Ken Thompson says "I think the major good idea in Unix was its clean and simple interface: open, close, read, and write."

Aside from inventing UNIX, Ken Thompson developed the first Master level chess playing computer called Belle with Joe H. Condon, in 1980.

Along with Dennis Ritchie, Ken Thompson received the ACM Turing award in 1983, for "for their development of generic operating systems theory and specifically for the implementation of the UNIX operating system.". In his Turing award lecture, Reflections On Trusting Trust, Ken Thompson described a hack that he placed into early UNIX systems: the C compiler would insert a back door whenever it compiled the login program, allowing Ken Thompson to access any UNIX system. The scheme was so fiendish that if you tried remove the back-door generating code from the source code and recompile the compiler, the compiler would reintroduce the back door generation into the source code!

Ken Thompson retired from Bell Labs in 2000.