Douglas McIlroy went to school and earned a Bachelor's degree in engineering physics from Cornell University in 1954 and a Ph.D. in applied mathematics from the Massachusetts Institute of Technology in 1959. In 1958, he joined Bell Labs. From 1965 to 1986, he was Head of Computer Research at Bell Labs. The UNIX operating system was invented in Bell Labs. In 1997, McIlroy retired from Bell Labs and wen to work as an Adjunct Professor at Dartmouth College's Computer Science Department.