Edsger Wybe Dijkstra

11 May 1930 – 6 August 2002

Professor Edsger Wybe Dijkstra, a noted pioneer of the science and industry of computing, died after a long struggle with cancer on 6 August 2002 at his home in Nuenen, the Netherlands.

Dijkstra was born in 1930 in Rotterdam, The Netherlands, the son of a chemist father and a mathematician mother. He graduated from the Gymnasium Erasmianum in Rotterdam and obtained degrees in mathematics and theoretical physics from the University of Leyden and a Ph.D. in computing science from the University of Amsterdam. He worked as a programmer at the Mathematisch Centrum, Amsterdam, 1952-62; was professor of mathematics, Eindhoven University of Technology, 1962-1984; and was the Burroughs Corporation research fellow, 1973-1984. He held the Schlumberger Centennial Chair in Computing Sciences at the University of Texas at Austin, 1984-1999, and retired as Professor Emeritus in 1999.

Dijkstra is survived by his wife of over forty years, Maria (Ria) C. Dijkstra Debets, by three children, Marcus J., Femke E., and computer scientist Rutger M. Dijkstra, and by two grandchildren.

Dijkstra was the 1972 recipient of the ACM Turing Award, often viewed as the Nobel Prize for computing. He was a member of the Netherlands Royal Academy of Arts and Sciences, a member of the American Academy of Arts and Sciences, and a Distinguished Fellow of the British Computer Society. He received the 1974 AFIPS Harry Goode Award, the 1982 IEEE Computer Pioneer Award, and the 1989 ACM SIGCSE Award for Outstanding Contributions to Computer Science Education. Athens University of Economics awarded him an honorary doctorate in 2001. In 2002, the C&C Foundation of Japan recognized Dijkstra "for his pioneering contributions to the establishment of the scientific basis for computer software through creative research in basic software theory, algorithm theory, structured programming, and semaphores".

Dijkstra is renowned for the insight that mathematical logic is and must be the basis for sensible computer program construction and for his contributions to mathematical methodology. He is responsible for the idea of building operating systems as explicitly synchronized sequential processes, for the formal development of computer programs, and for the intellectual foundations for the disciplined control of nondeterminacy. He is well known for his amazingly efficient shortest path algorithm and for having designed and coded the first Algol 60 compiler. He was famously the leader in the abolition of the GOTO statement from programming.

Dijkstra was a prodigious writer. His entire collection of over thirteen hundred written works was digitally scanned and is accessible at http://www.cs.utexas.edu/users/EWD. He also corresponded regularly with hundreds of friends and colleagues over the years --not by email but by conventional post. He strenuously preferred the fountain pen to the computer in producing his scholarly output and letters.

Dijkstra was notorious for his wit, eloquence, and way with words, such as in his remark "The question of whether computers can think is like the question of whether submarines can swim"; his advice to a promising researcher, who asked how to select a topic for research: "Do only what only you can do"; and his remark in his Turing Award lecture "In their capacity as a tool, computers will be but a ripple on the surface of our culture. In their capacity as intellectual challenge, they are without precedent in the cultural history of mankind."

Dijkstra enriched the language of computing with many concepts and phrases, such as structured programming, separation of concerns, synchronization, deadly embrace, dining philosophers, weakest precondition, guarded command, the excluded miracle, and the famous "semaphores" for controlling computer processes. The Oxford English Dictionary cites his use of the words "vector" and "stack" in a computing context.

Dijkstra enjoyed playing Mozart for his friends on his Boesendorfer piano. He and his wife had a fondness for exploring state and national parks in their Volkswagen bus, dubbed the Touring Machine, in which he wrote many technical papers.

Throughout his scientific career, Dijkstra formulated and pursued the highest academic ideals of scientific rigour untainted by commercial, managerial, or political considerations. Simplicity, beauty, and eloquence were his hallmarks, and his uncompromising insistence on elegance in programming and mathematics was an inspiration to thousands. He judged his own work by the highest standards and set a continuing challenge to his many friends to do the same. For the rest, he willingly undertook the role of Socrates, that of a gadfly to society, repeatedly goading his native and his adoptive country by remarking on the mistakes inherent in fashionable ideas and the dangers of time-serving compromises. Like Socrates, his most significant legacy is to those who engaged with him in small group discussions or scientific correspondence about half-formulated ideas and emerging discoveries. Particularly privileged are those who attended his reading groups in Eindhoven and Austin, known as the "Tuesday Afternoon Clubs".

At Dijkstra's passage, let us recall Phaedo's parting remark about Socrates: "we may truly say that of all the men of his time whom we have known, he was the wisest and justest and best."