1952 Kristen Nygaard starts work in Operations Research including writing simulation models. Problem: how to conceptualize complex real world. Since the very beginning Simula intended to be both system description and programming language.
1960 Algol 60 with its true recursive block mechanism structure based on stack principle. All important control structures introduced. Simula intended as a package with preprocessor to Algol 60.
1962 Ole-Johan Dahl and Kristen Nygaard meet in Norwegian Computing Center (NCC) in Oslo. First formal language proposal presented at the IFIP 62 World Congress in Munich.
1962 Simula project supported by UNIVAC, that resulted in UNIVAC 1107 installation in NCC in 1963.
1963 Conflict between strict Algol stack mechanism and Simula's sophisticated simulation facilities oriented more to queue principle. Preprocessor idea abandoned, Simula to be an independent Algol based language.
1963 Ole-Johan Dahl works on a new storage allocation scheme based on a two dimensional list of free areas.
1964 Original idea of passive customers moving through a network of active components (activity approach) became a limiting factor. Other way round possible - active customers moving through a passive network. This resulted in a unifying general process concept:
System = set of interacting quasiparallel processes.
1964 First prototype of Simula compiler running on NCC's UNIVAC 1107 in December, Simula I manual appeared in May 1965. During the first year Simula applied to a wide area of Operations Research problems.
1965,66 Simula I used in Sweden, Germany, USA (Burroughs B5500), Soviet Union (URAL 16) and other countries. Effort to introduce and teach the language.
1965 Tony Hoare's record class concept presented in Algol bulletin. After a careful examination, Nygaard and Dahl accept the ideas, but a sort of generalized concept still missing.
1966 Introducing the idea of prefixing. Processes (later objects) made of two layers: prefix layer, main layer. Idea of subclasses. Nygaard and Dahl start work on a new general high-level language.
1967 (May). Simula 67 officially introduced by Dahl and Nygaard at the IFIP TC 2 Working Conference on Simulation Languages in Lysebu near Oslo.
1967 (June). Definition of Simula 67 standard called Common Base Standard.
1968 First meeting of Simula Standards Group (SSG). After accepting string handling and I/O done by Bjorn Myhrhaug, Simula formally frozen.
1973 Association of Simula Users (ASU) founded. Simula used in more than 250 sites that year.
Implementations Of SIMULA 1 and SIMULA 67:
1969 CDC 3300, 3600 (Norway - University of Oslo, NDRE)
1971 UNIVAC 1100 (NCC)
1972 IBM 360/370 (NCC)
1972 CII 10070, IRIS 80 (France)
1973/74 CDC 6000 (France, Netherlands), CDC Cyber 70 (NDRE)
1975 DEC 10 (Sweden) etc.
(Source: Jan Rune Holmevik: Compiling Simula)