At the Mathematical Centre a major project was building the ARMAC computer. For its official inauguration in 1956, Dijkstra devised a program to solve a problem interesting to a nontechnical audience: Given a network of roads connecting cities, what is the shortest route between two designated cities? The best known algorithms had running times which grew as the cube of the network’s size; the running time of Dijkstra’s algorithm grew only as the square. Developed in 20 minutes while Dijkstra was relaxing on a café terrace with his fiancée, Maria (Ria) C. Debets, his Shortest Path algorithm is still used in such applications as packet-switching software for computer communications.

When Dijkstra and Maria Debets married in 1957, the marriage rites required him to state his profession. When he stated that he was a programmer, the authorities objected that there was no such profession, and the marriage certificate instead identifies him as a theoretical physicist.

While at the Mathematical Center, Dijkstra worked on the very important “real-time interrupt” problem, which became the topic of his Ph.D. thesis.  Several computer manufacturers of the day were facing the same problem, but they had not approached the problem with the rigor that Dijkstra applied to it.

At the Mathematical Center, Dijkstra and J.A.Zonneveld developed the first compiler for Algol-60, a high-level programming language designed by an international committee. He was probably the first to introduce the notion of a “stack” for translating recursive programs, reporting this seminal work in a short article. In the Oxford English Dictionary, the terms “vector” and “stack” in a computing context are attributed to Dijkstra.

In 1962 Dijkstra was appointed Professor of Mathematics at the Eindhoven University of Technology. There he built the THE operating system (named for the university, then known as Technische Hogeschool te Eindhoven), which has influenced the design of many subsequent operating systems. It introduced a number of design principles which have become part of the working vocabulary of every professional programmer. Introducing the reprint of Dijkstra’s article on the THE operating system in the 25th Anniversary issue of Communications of the ACM, the Editor-in-Chief wrote, “This project initiated a long line of research in multilevel systems architecture—a line that continues to the present day because hierarchical modularity is a powerful approach to organizing large systems.”

In 1968, Dijkstra published a brief letter to the editor in Communications of ACM, titled “Go To statement considered harmful”, arguing that the GO TO statement, found in many high-level programming languages, is a major source of errors, and should therefore be eliminated. 

Dijkstra’s “Notes on Structured Programming,”  has had far-reaching impact on all areas of computer science, from the teaching of the first courses in programming to the design of complex software. Mathematical analyses of program design and specifications have become central activities in computer science research.

Dijkstra’s acceptance speech for the 1972 ACM Turing Award, titled “The humble programmer”, includes a vast number of observations on the evolution of programming as a discipline and prescriptions for its continued growth. It is required reading for any aspiring computer scientist.

Returning to The Netherlands in February 2002, Dijkstra died in Nuenen on 6 August 2002. 

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