The many dimensions of Kristen Nygaard, creator of Object-Oriented Programming and the Scandinavian School of System Development

Professor Kristen Nygaard (1926-2002) was a multi-talented scientist whose achievements were amply honoured in his later years. For general readers of Computer Science history Nygaard will be recognized as the creator with Professor Ole-Johan Dahl of the SIMULA programming languages and object-oriented programming. But Nygaard also had a social and political engagement that over the years brought him from a liberal-democratic to a socialist position where solidarity and empowerment were the major chords. This paper gives a condensed descriptive tour of the life of this many-sided computer scientist with an emphasis on how the scientific and political sides of Nygaard worked hand in hand, leading to his active cooperation with the trade unions and making him a strong advocator of the Scandinavian School of System Development and Participatory Design.