Douglas McIlroy

Malcolm Douglas McIlroy
McIlroy (left) with former colleague Dennis Ritchie at the Japan Prize Foundation in May 2011
Born	1932 (age 84–85)
Alma mater	Cornell University (B.S., Engineering Physics, 1954) Massachusetts Institute of Technology (Ph.D., Applied Mathematics, 1959)
Occupation	mathematician, engineer, programmer
Known for	Unix pipelines, software componentry, spell, diff, sort, join, graph, speak, tr

Malcolm Douglas McIlroy (born 1932) is a mathematician, engineer, and programmer. As of 2007 he is an Adjunct Professor of Computer Science at Dartmouth College. McIlroy is best known for having originally developed Unix pipelines, software componentry and several Unix tools, such as spell, diff, sort, join, graph, speak, and tr.

His seminal work on software componentization makes him a pioneer of component-based software engineering and software product line engineering.

McIlroy earned his Bachelor's degree in engineering physics from Cornell University in 1954, and a Ph.D. in applied mathematics from MIT in 1959 for his thesis On the Solution of the Differential Equations of Conical Shells. He taught at MIT from 1954 to 1958.

McIlroy joined Bell Laboratories in 1958; from 1965 to 1986 was head of its Computing Techniques Research Department (the birthplace of the Unix operating system), and thereafter was Distinguished Member of Technical Staff.

From 1967 to 1968, McIlroy also served as a visiting lecturer at Oxford University.

In 1997, McIlroy retired from Bell Labs, and took a position as an Adjunct Professor in the Dartmouth College Computer Science Department.