Edsger W. Dijkstra

Edsger W. Dijkstra
Born	Edsger Wybe Dijkstra (1930-05-11) May 11, 1930 Rotterdam, Netherlands
Died	August 6, 2002(2002-08-06) (aged 72) Nuenen, Netherlands
Occupation(s)	Computer scientist, mathematician, essayist
Years active	1952–1999
Known for	Shortest path problem, THE multiprogramming system, structured programming, EWD series of technical reports

Edsger Wybe Dijkstra ( ; 11 May 1930 – 6 August 2002) was a prominent Dutch figure in computer science, programming, software engineering, mathematics, and scientific essay writing.

Originating from Rotterdam, Dijkstra pursued studies in mathematics and physics at the University of Leiden. He became the Netherlands' inaugural computer programmer at the Mathematical Centre in Amsterdam between 1952 and 1962. In 1956, he introduced the concept of the shortest path problem and, alongside Jaap A. Zonneveld in 1960, developed the initial compiler for ALGOL 60. By 1962, he joined the Mathematics Department at the Technische Hogeschool Eindhoven, where he designed the influential THE multiprogramming system during the late 1960s, pioneering software-driven paged virtual memory techniques.

In August 1973, Dijkstra assumed the role of sole research fellow at Burroughs Corporation, where he authored nearly 500 technical reports compiled in his "EWD" series. He accepted the Schlumberger Centennial Chair at the University of Texas at Austin in 1984 and remained there until his retirement in 1999. Subsequently, he returned to Nuenen in the Netherlands, where he passed away in 2002 after a battle with cancer.

Dijkstra was honored with the 1972 Turing Award for his foundational work on structured programming languages. Shortly before his passing, he received the ACM PODC Influential Paper Award recognizing his contributions to self-stabilization in distributed computing; this accolade was later renamed the Dijkstra Prize to commemorate him.

Early years

Edsger W. Dijkstra was born in Rotterdam. His father worked as a chemist and served as president of the Dutch Chemical Society; he also taught chemistry before becoming a school superintendent. His mother held qualifications in mathematics but did not engage in formal employment.

Although initially inclined toward law and diplomacy, Dijkstra followed his parents’ advice and enrolled at the University of Leiden after completing secondary education in 1948, focusing on mathematics, physics, and subsequently theoretical physics.

During the early 1950s, as electronic computers began to emerge, Dijkstra’s supervisor Professor Johannes Haantjes introduced him to Adriaan van Wijngaarden, who led the Computation Department at the Mathematical Centre in Amsterdam. Van Wijngaarden appointed him as the first officially recognized programmer in the Netherlands in March 1952.

While his initial commitment was to physics, Dijkstra gradually redirected his attention toward computing. He recounted a defining conversation with Van Wijngaarden that persuaded him to treat programming as a rigorous discipline rather than merely theoretical physics:

When Dijkstra married Maria "Ria" C. Debets in 1957, his declaration of occupation as "programmer" was initially rejected by Dutch officials because programming had not yet been formally acknowledged as a profession.

In 1959, he obtained his PhD from the University of Amsterdam with a dissertation entitled 'Communication with an Automatic Computer', which described assembly language programming for the Netherlands’ first commercial computer, the Electrologica X1. His doctoral advisor was Van Wijngaarden.

Mathematisch Centrum, Amsterdam

From 1952 until 1962, Dijkstra was employed at the Mathematisch Centrum in Amsterdam, where he worked alongside Bram Jan Loopstra and Carel S. Scholten on constructing a computer. Their approach involved establishing a rigorous methodology by initially defining the hardware-software interface through a detailed programming manual. This ensured that hardware engineers followed strict guidelines while Dijkstra focused on developing software for the machine that was still under construction. This period underscored for him the critical role of precise documentation and meticulous design in reducing debugging efforts.

In 1956, Dijkstra devised and resolved the shortest path problem to demonstrate the capabilities of the ARMAC computer, although the findings were published only in 1959 due to limited outlets for computing research at the time. Together with a colleague, he created the earliest compiler for ALGOL 60 by August 1960—predating other similar projects by more than a year—representing a significant milestone in the evolution of structured programming.

Eindhoven University of Technology

Dijkstra accepted a professorship in mathematics at Eindhoven University of Technology in 1962, which at that time did not have a formal computer science department. He aimed to foster a collaborative computer science group within the mathematics faculty, an approach that was unconventional during that era. In the late 1960s, he developed the THE operating system, named after the institution’s former name, Technische Hogeschool Eindhoven. This operating system became influential for its pioneering implementation of software-based paged virtual memory, shaping future operating system designs.

Burroughs Corporation

In August 1973, Dijkstra joined Burroughs Corporation, known for its cutting-edge computer architecture innovations, as their sole research fellow. His research activities were mainly conducted from his home office in Nuenen, with occasional visits to Burroughs’ research facilities. As a result, he reduced his university commitments to one day per week—Tuesdays—which evolved into the 'Tuesday Afternoon Club,' a seminar where he and colleagues rigorously analyzed scientific papers across all facets including notation and clarity. After relocating in 1984 to the University of Texas at Austin, he established a similar discussion group there.

Throughout his time at Burroughs, Dijkstra was extremely productive, authoring nearly 500 technical reports within his EWD series that were circulated privately among peers.

The University of Texas at Austin

In 1984, Dijkstra assumed the Schlumberger Centennial Chair position within the Computer Science Department at the University of Texas at Austin.

Last years

Dijkstra remained active professionally in Austin until his retirement in November 1999. To commemorate over four decades of foundational work in computing science, the department hosted a symposium celebrating his 70th birthday in May 2000.

He and his wife moved back to his hometown of Nuenen in the Netherlands, where he spent his final months. Although he wished to retire in Austin, he preferred to pass away in his native country. After a prolonged battle with cancer, he died on 6 August 2002. He is survived by his wife and their three children: Marcus, Femke, and Rutger M. Dijkstra, who is also a computer scientist.

Character

Dijkstra was regarded as a distinctive figure within the computing science community. In the introduction to his 1976 book A Discipline of Programming, he remarked: "For the absence of a bibliography I offer neither explanation nor apology." This lack of references in most of his publications underscored his strong belief in intellectual independence.

In his role as an academic, Dijkstra treated teaching as rigorous research rather than a mere obligation. His lectures were marked by unusual pauses, partly because English was not his native tongue and partly to allow time for careful reflection. Rather than concentrating on computer science topics, his courses emphasized the presentation of mathematical proofs. At the beginning of each term, he took photographs of students to aid in memorizing their names and typically refrained from using textbooks—except possibly those he authored himself. His classes involved writing proofs on blackboards and fostering student contributions, which he scrutinized thoroughly. Assignments were demanding and meticulously checked, while final examinations were conducted orally over several hours across a week.

Dijkstra also had a unique approach to evaluating job applicants; for instance, during an interview in 1990, he challenged Vladimir Lifschitz with a puzzle that Lifschitz solved before joining the faculty at Austin.

Use of technology

For many years, Dijkstra deliberately avoided using computers. Only after encouragement from colleagues did he begin using a Macintosh for email and internet browsing. He never composed articles on a computer, preferring instead to use his typewriter and later a Montblanc Meisterstück fountain pen. He rejected word processors entirely, believing that writing should be done without drafts or extensive revisions, with all ideas fully formed mentally beforehand. The majority of his works were produced independently; he personally managed all correspondence and expressed individual thanks to contributors for his sixtieth birthday Festschrift.

In his 1972 essay The Humble Programmer, Dijkstra highlighted that computing scientists create categories of computations rather than merely write programs. He was critical of incorporating software engineering into academic computer science, labeling it "The Doomed Discipline" due to its contradictory aims and its premise of "How to program if you cannot."

Personal life

Dijkstra maintained a simple and austere way of living. The home he shared with his wife in Nuenen was modest and unpretentious. He did not own a television, video player, or mobile phone and avoided going to cinemas. A skilled pianist and admirer of classical music, he especially appreciated Mozart and attended concerts during his time in Austin.

Essays and other writing

Dijkstra was an exceptionally productive essayist, having authored more than 1,300 papers noted for their clarity and conciseness. His body of work included essays, parables, fairy tales, and cautionary pieces primarily centered on mathematics and computer science. He routinely distributed copies among select colleagues who then shared them within restricted scientific networks.

EWDs

Dijkstra was recognized for meticulously drafting manuscripts with his fountain pen, assigning them the label EWD—his initials. The EWD series began after he relocated from the Mathematical Centre in Amsterdam to Eindhoven University of Technology. Following a year-long period of writer's block, he resumed sharing photocopies of new EWDs with colleagues who further disseminated them worldwide. These brief documents—comprising trip reports, letters, and speeches—covered topics in computer science and mathematics over four decades. Nearly all EWDs produced after 1972 were handwritten, rarely exceeding 15 pages, and numbered sequentially. The final entry, No. 1318, is dated 14 April 2002. Known within computer science as the EWD reports, over 1,300 have been digitized and are available online through the University of Texas Dijkstra archive.

Writing style

Dijkstra’s early commitment to simplicity was shaped by his mother’s counsel to keep proofs under five lines. Known for his sharp wit and directness, he famously stated, "The question of whether Machines Can Think (…) is about as relevant as the question of whether Submarines Can Swim." His guidance for researchers was concise: "Do only what only you can do." Despite his limited social aptitude and outspoken nature, Dijkstra was a vocal critic of teaching BASIC, reflecting his dedication to a rigorous approach in computer science education.

Recurring themes

In his clever essays, Dijkstra portrayed himself as the chairman of a fictional enterprise named Mathematics, Inc., which commercialized mathematical theorem production similarly to how software firms market programs. He chronicled the company's operations and challenges through various EWD papers. Mathematics Inc. had developed a proof for the Riemann Hypothesis but faced difficulties collecting royalties from mathematicians using it, since the proof remained a trade secret. Many proofs were hastily created, necessitating ongoing maintenance. A significant achievement was the Standard Proof for Pythagoras' Theorem, which consolidated more than 100 previously incompatible proofs. Dijkstra described Mathematics Inc. as "the most exciting and most miserable business ever conceived," claiming it held over 75% of the global market share according to EWD 443 (1974).

Legacy

Dijkstra was honored with the 1972 Turing Award for championing structured programming—a methodology that prioritizes structured control flow over unstructured jumps such as Goto statements. His influential 1968 letter titled "Go To statement considered harmful" ignited considerable discussion and helped shape contemporary programming standards.

His most renowned achievement is Dijkstra's algorithm, extensively taught within computer science curricula and implemented in network routing protocols like OSPF and IS-IS.

Additional significant contributions include the Shunting yard algorithm for expression parsing; the layered architecture of the "THE" operating system; the Banker's algorithm for managing resource allocation; and the semaphore mechanism for synchronizing processes. In distributed systems, he introduced self-stabilization, a technique that guarantees fault tolerance.

Awards and honors

Among Dijkstra's distinguished recognitions are:

• Election to the Royal Netherlands Academy of Arts and Sciences (1971)
• Designation as Distinguished Fellow by the British Computer Society (1971)
• Receipt of the Association for Computing Machinery's A.M. Turing Award (1972)
• Winner of the Harry H. Goode Memorial Award from the IEEE Computer Society (1974)
• Foreign Honorary Membership in the American Academy of Arts and Sciences (1975)
• Honorary Doctor of Science degree from Queen's University Belfast (1976)
• Charter membership as Computer Pioneer from the IEEE Computer Society (1982)
• ACM/SIGCSE Award recognizing Outstanding Contributions to Computer Science Education (1989)
• Named an ACM Fellow by the Association for Computing Machinery (1994)
• Honorary doctorate awarded by the Athens University of Economics & Business, Greece (2001)

The Distinguished Fellow award by the British Computer Society was established in 1969 and first bestowed upon Dijkstra in 1971.

In 1990, UT Austin’s Department of Computer Science organized a seminar celebrating Dijkstra’s 60th birthday, featuring international speakers and a compilation of scholarly papers.

Japan’s C&C Foundation honored Dijkstra posthumously in 2002 for his pioneering work in software theory and structured programming; his family accepted the award on his behalf.

Shortly before passing away, he was awarded the ACM PODC Influential-Paper Award recognizing his contributions to distributed computing through self-stabilization research; this prize was renamed the Dijkstra Prize in 2003 to honor his legacy.

In 2005, Loyola University Chicago’s Computer Science Department inaugurated the Dijkstra Award for Outstanding Academic Achievement in Computer Science, presented annually to top graduating students based on GPA and faculty nomination.

The University of Texas at Austin established the Edsger W. Dijkstra Memorial Lecture in 2010 with support from Schlumberger, featuring Tony Hoare as its inaugural speaker.

Notable articles

• Republished in First appeared in
• —. "The Humble Programmer". Comm. ACM. 15 (10): 859–866.
• —. "On the Cruelty of Really Teaching Computer Science". Comm. ACM. 32.

See also

• Go To Statement Considered Harmful
• On the Cruelty of Really Teaching Computer Science
• List of pioneers in computer science