Communications of the ACM

Simplicity, beauty, and eloquence were his hallmarks, and his uncompromising insistence on elegance in programming and mathematics was an inspiration to thousands.

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.

Throughout his scientific career, Dijkstra formulated and pursued the highest academic ideals of scientific rigor 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 in small group discussions or scientific correspondence with him about half-formulated ideas and emerging discoveries. Particularly privileged are those who attended his research groups in Eindhoven and Austin, known as the "Tuesday Afternoon Clubs."

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 in Amsterdam from 1952–62; was professor of mathematics at Eindhoven University of Technology from 1962–1984; and was the Burroughs Corporation research fellow from 1973–1984. He held the Schlumberger Centennial Chair in Computing Sciences at the University of Texas at Austin from 1984–1999, and retired as Professor Emeritus in 1999.

Dijkstra is survived by his wife of 45 years, Maria (Ria) C. Dijkstra Debets, by three children, Marcus J., Femke E., and computer scientist Rutger M. Dijkstra, and by two grandchildren.

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.

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."