How It All Began

It all began at Bell Labs, the research lab of AT&T, one of the largest and most powerful companies of our time. Ironically, AT&T was not interested in developing and selling computers or operating systems. In fact, the U.S. Department of Justice did not allow AT&T to sell software. However, AT&T’s existing systems, made up of people and paper, were in danger of being overwhelmed in the boom of the 1960s. By the 1970s, the phone business was in jeopardy. Out of desperation and need, Ken Thompson of AT&T set out to develop what no computer company was ready to provide— a multiuser, multiprocessing operating system to be used in-house for its own information-processing department. Specifically, the goal was an operating system to support several programmers simultaneously in a more hospitable environment.

What follows is an account of major dates and events in the development cycle of the UNIX operating system.