Kristen attended Fagerborg high school, Pilestredet, Oslo. Of course these were difficult years due to World War II, and he later recounted many war-time stories from this period. At first the country declared itself neutral. However, the Germans invaded Norway on 9 April 1940, bombs were dropped in the Oslo area, and the Norwegian authorities fled from the city. Resistance took place until 10 June 1940 when Norway surrendered and the Germans took control. Teachers were required to sign a declaration of loyalty to the Nazis and promise they would teach Nazi ideology. The teachers resisted the Nazi moves. Teaching stopped but restarted in the autumn of 1940. During 1942 there were mass arrests of teachers but schools continued to operate. Nygaard graduated from Fagerborg high school in 1945. He then studied science at the University of Oslo where his main interest was first in astronomy, and later in applied mathematics. In 1948 he took up a full-time appointment with the Norwegian Defence Research Establishment. He writes that he :-
.... started his conscript service at the Norwegian Defence Research Establishment in 1948 as assistant to Jan V Garwick - the father of computer science in Norway. Their first main task was to carry out resonance absorption calculations related to the construction of Norway's first nuclear reactor. After extensive work had been invested in a traditional numerical approach, Monte Carlo simulation methods (by "hand") were successfully introduced instead in 1949-1950. [I] headed the "computing office" until mid 1952, and then became a full time operational research worker.Nygaard married Johanna Ur in Oslo on 27 January 1951. Johanna, who was born in Ardal in Ryfylke on 13 December 1924, was the daughter of the farmer Bertel Ur and his wife Otelie Lunde. Kristen and Johanna Nygaard had three children including twins, a son and daughter born on 16 May 1951 in Oslo.
We have seen in the quote above that Nygaard was using Monte Carlo methods in his work for the Norwegian Defence Research Establishment. In 1952 he published On the solution of integral equations by Monte-Carlo methods as a Norwegian Defence Research Establishment Report. Four years later he was awarded a Master's Degree by the University of Oslo for a thesis Theoretical Aspects of Monte Carlo Methods. In 1959 he was cofounder of the Norwegian Operational Research Society and became its first chairman, holding the position until 1964. In 1960 he changed his employment :-
In May 1960 [I] left the Norwegian Defence Research Establishment to build up the Norwegian Computing Centre as a research institute in computer science, operational research and related fields. Many of the civilian tasks turned out to present the same kind of methodological problems: the necessity of using simulation, the need of concepts and a language for system description, lack of tools for generating simulation programs. This experience was the direct stimulus for the ideas which in 1961 initiated the SIMULA development.SIMULA, which Nygaard refers to in this quotation, is the object-oriented programming language of which he was the co-inventor. It is the achievement for which he is today most famed. He wrote a letter on 5 January 1961 to the operational research expert Charles Salzmann explaining where his thinking was on the development of the language :-
The status of the Simulation Language (Monte Carlo Compiler) is that I have rather clear ideas on how to describe queueing systems, and have developed concepts which I feel allow a reasonably easy description of large classes of situations. I believe that these results have some interest even isolated from the compiler, since the presently used ways of describing such systems are not very satisfactory. I hope that later developments, for which I have a number of ideas, will include e.g. stochastic inventory situations amongst the situations which may be described by the language. The work on the compiler could not start before the language was fairly well developed, but this stage seems now to have been reached. The expert programmer who is interested in this part of the job will meet me tomorrow. He has been rather optimistic during our previous meetings.The 'expert programmer' that Nygaard referred to in this letter was Ole-Johan Dahl, now recognised as the other co-inventor of SIMULA. Nygaard rose rapidly in the Norwegian Computing Centre, becoming its Director of Research in 1962. In 1975 he was appointed to a professorship at Aarhus University, Denmark. One year later he returned to Norway when he was appointed as a professor at Oslo University. The appointment was part-time until 1984 when it became a full-time appointment. He remained in this post until he retired in 1996, although he did spend time at other institutions such as Stanford University, Palo Alto, USA in 1987. Also while in the United States in 1987 he was a Visiting Scientist at Xerox PARC in Palo Alto, and a consultant at Apple Computer's Advanced Technology Group where he also gave lectures.
If we ended this biography here we would get a totally false impression of Nygaard for he would simply come across as a brilliant computer scientist and mathematician. Certainly he was exactly that, but much more :-
In the 1970's, Nygaard's research interests increasingly turned to the impact of technology on the labour movement, and he became involved in other political, social and environmental issues. He was the first chairman of the environment protection committee of the Norwegian Association for the Protection of Nature. He was also the Norwegian representative for the Organization for Economic Cooperation and Development's activities on information technology. He also helped run an experimental program to create humane living conditions for alcoholics. In the mid 1960's he became a member of the National Executive Committee of the Norwegian party Venstre, a left-wing non-socialist party, and chairman of that party's strategy committee. In 1988 he became chairman of a group that successfully opposed Norway's membership in the European Union.Even after Norway voted "no" to the European Union in a referendum on 28 November 1994, Nygaard did not give up opposing the European Union. He worked hard during 1996 to establish The European Anti-Maastricht Movement which was to bring together those inside and outside the European Union opposed to the Maastricht Treaty and Economic and Monetary Union.
He received many honours for his remarkable contributions with the introduction of SIMULA. For example he was awarded the Norbert Wiener Prize in October 1990 from the American Association of Computer Professionals for Social Responsibility. Computerworld presented him with a prize in 1992 for:-
... having made Norway known internationally in the information technology field.In 1999 the co-inventors of SIMULA, Nygaard and Dahl, were awarded the Rosing Prize by the Norwegian Data Association:-
... for exceptional professional achievements.The Object Management Group awarded Nygaard an Honorary Fellowship for:-
... his originating of object technology concepts.Nygaard and Dahl received the A M Turing Award for 2001 by the Association for Computing Machinery:-
For ideas fundamental to the emergence of object oriented programming, through their design of the programming languages Simula I and Simula 67.The Association for Computing Machinery gave this appreciation of the contributions of Nygaard and Dahl:-
Their work has led to a fundamental change in how software systems are designed and programmed, resulting in reusable, reliable, scalable applications that have streamlined the process of writing software code and facilitated software programming. Current object-oriented programming languages include C++ and Java. They are both widely used in programming a wide range of applications from large-scale distributed systems to small, personal applications, including personal computers, home entertainment devices, and standalone arcade applications. The A M Turing Award carries a $25,000 prize. The discrete event simulation language (Simula I) and general programming language (Simula 67) developed by Dahl and Nygaard at the Norwegian Computing Centre in Oslo, Norway in the 1960's, led the way for software programmers to build software systems in layers of abstraction. With this approach, each layer of a system relies on a platform implemented by the lower layers. Their approach has resulted in programming that is both accessible and available to the entire research community.Also in 2001 the two co-inventors received the John von Neumann Medal, awarded by the Institute of Electrical and Electronic Engineers:-
For the introduction of the concepts underlying object-oriented programming through the design and implementation of SIMULA 67.He also received honorary doctorates from Lund University, Sweden (June 1990) and Aalborg University, Denmark (June 1991). In August 2000, he was made a Commander of the Order of Saint Olav by King Harald V of Norway.
Nygaard died after suffering a heart attack while spending the weekend at his family's holiday home at Tjome.
Article by: J J O'Connor and E F Robertson