Jack Dennis

Jack Bonnell Dennis (born October 13, 1931)[1] is a computer scientist and Emeritus Professor of Computer Science and Engineering at Massachusetts Institute of Technology.

Jack Dennis
Jack Dennis.jpg
Born(1931-10-13)October 13, 1931
EducationMassachusetts Institute of Technology
AwardsIEEE John von Neumann Medal, Association for Computing Machinery (ACM) Special Interest Group on Operating Systems (SIGOPS) Hall of Fame, Member of the National Academy of Engineering (NAE)
Scientific career
FieldsComputer science

The work of Dennis in computer systems and computer languages is recognized to have played a key role in hacker culture. As an Massachusetts Institute of Technology faculty member he sponsored easier access to computer facilities at MIT during the early development of the subculture.[2][3] Much of what would later become Unix came from his early collaboration with Dennis Ritchie and Ken Thompson. This collaborative and open philosophy lives on today.

Dennis was also a member of the historic Tech Model Railroad Club, which incubated much of the early slang and traditions of hacking.

Early life and educationEdit

Dennis graduated from the Massachusetts Institute of Technology (MIT) as Bachelor of Science (1953), Master of Science (1954), and Doctor of Science (1958).[4] His doctoral thesis analyzed the relation between mathematical programming problems and electrical networks.[5] After completing his doctorate, Dennis became part of the MIT's Department of Electrical Engineering and Computer Science's faculty, being promoted to full professor in 1969.


As a professor at MIT, Dennis was influential in the work of students Alan Kotok, fellow professors Marvin Minsky and John McCarthy.[2] He gave young programmers access to multi-million dollar computers and allowed them to see where their abilities could take them, inspiring a generation of MIT graduates who would shape the computer industry at DEC, Xerox Parc and ARPA.

Dennis was one of the founders of the Multics project. His most important contribution to the project was the concept of the single-level memory. Multics was not fully successful as a commercial project, but it was important because it influenced the design of many other computer operating systems, most importantly the direct inspiration for Ken Thompson (who also worked on the project) to design the first incantation of Unix. In recognition of his work on the Multics project, Dennis was elected as IEEE Fellow.

Dennis' research at the MIT focused in Computer Theory and Computer Systems, specifically:

  • Theoretical Models for Computation
  • Computation Structures
  • Structure of Computer Systems
  • Semantic Theory for Computer Systems
  • Semantics of Parallel Computation
  • Computer System Architecture

Dennis has also worked as an independent consultant and research scientist on projects related with parallel computer hardware and software since his retirement from MIT in 1987. He has worked with the NASA Research Institute for Advanced Computer Science as Visiting Scientist, with the Architecture Group of Carlstedt Elektronik (Gothenburg, Sweden), and with Acorn Networks, Inc., as Chief Scientist.[5]

A great part of Dennis' career has been devoted to non-von Neumann models of computation, architecture, and languages, where programs are not attached to a program counter. Along with his students, Dennis adopted the concepts of "single-assignment" and dataflow, in which instructions are executed as soon as data are available (this specific model is called "static" in contrast to Arvind's "dynamic").[6]

Awards and recognitionsEdit


  1. ^ a b "Jack Dennis". Computer History Museum. Retrieved October 14, 2020.
  2. ^ a b Levy, Steven (2010). Hackers: Heroes of the Computer Revolution - 25th Anniversary Edition. O'Reilly Media. p. 49. ISBN 978-1449388393.
  3. ^ "Jack Dennis". SoldierX. Retrieved January 7, 2013.
  4. ^ Wildes, Karl L. (1985). A Century of Electrical Engineering and Computer Science at MIT, 1882-1982. The MIT Press. p. 345. ISBN 978-0262231190.
  5. ^ a b c "Jack B. Dennis 1984 Eckert-Mauchly Award Recipient". IEEE Computer Society. Archived from the original on October 18, 2013. Retrieved January 6, 2013.
  6. ^ Treleaven, Philip C. (1987). Future Parallel Computers: An Advanced Course, Pisa, Italy, June 9-20, 1986, Proceedings (Lecture Notes in Computer Science). Springer. p. 98. ISBN 978-3540182030.
  7. ^ "Dennis awarded IEEE John von Neumann Medal". MIT News. Retrieved January 6, 2013.
  8. ^ "Dennis Selected for ACM SIGOPS Hall of Fame". MIT News. Retrieved January 6, 2013.
  9. ^ "CSAIL PI Jack Dennis Named to NAE". CSAIL, MIT. Archived from the original on June 9, 2013. Retrieved January 6, 2013.

External linksEdit