Ritchie graduated from the Harvard in physics and applied mathematics. While working at the Bell Telephone Laboratories, in 1969 he and Ken Thompson played a leading role in the creation of the UNIX operating system; and in 1972 Ritchie developed the C programming language. He continued to work for Bell Laboratories and its successors until his retirement in 2007. In 2011 he was awarded the Japan Prize for Information and Communications for his work on UNIX.