On the Development of Simula 67

The Simula 67 language was developed by Kristen Nygaard and myself during the period 1962-67. The project was started as the result of an initiative by Kristen Nygaard, who saw the need for a language for simulation modelling. The talk will consentrate on technical and cultural aspects.

We decided at an early stage that the language should be based on Algol 60, carrying on central principles in Algol, such as the block concept, orthogonality, programming swecurity, and execution efficiency. Although the initial aim was to create a simulation language, concepts such as object classes with "inheritance" have proved to be of importance for system development and programming in general. The combination of classes and Algol-like block structure is an important element of the language, but has entailed technical problems which will be discussed.