References to the Simula programming language are to two related simulation languages, Simula I and Simula 67.
The origins to Simula go back to Kristen Nygaard, who began working on computer simulation programs in 1957. Looking for a way to better describe system operations, he developed ideas for a formal computer language for describing a system. He teamed up with Ole-Johan Dahl in 1962, and together they developed a language, heavily influenced by ALGOL 60 and, to a lesser extent, by Simscript, which became SIMULA I, the "I" representing the Roman numeral for "one" rather than the letter. SIMULA I was a special-purpose programming language used to simulate discrete event systems. The language was fully operational on a UNIVAC 1107 computer by 1965.
In 1966, Dahl and Nygaard extended the concept of record class construct, introduced by C.A.R. Hoare, with prefixing and other features, presenting a paper on Class and Subclass declarations at the International Federation for Information Processing (IFIP) working conference on simulation languages in 1967, and this became the first formal declaration of Simula 67. In early 1968, SIMULA 67 was standardized by the SIMULA Standards Group.
Simula I is the predecessor of Simula 67. Older references to Simula will be a reference to Simula I but, more often, Simula 67 is intended.
Simula influenced the development of Smalltalk and later object-oriented programming languages, such as BETA.
In the late 1960s and early 1970s, the main implementations of Simula were for the UNIVAC 1100, System/360 and System/370, CDC 3000, and TOPS-10. These implementations were ported to other platforms.
Simula 87 was introduced in 1987 and is the most recent standard implementation of the language. Implementations of Simula 87 include GNU Cim, Lund Simula, Simula AS, and Portable Simula Revisited.
The Simula Research Laboratory is a non-profit Norwegian organization affiliated with the University of Oslo. Named for the Simula programming language, the organization conducts basic research into networks and distributed systems, scientific computing, and software engineering, and is not specifically involved in the development of the programming language.
A Simula program is made up of sequences of instructions that are known as blocks, acting independently to varying degrees, but which are combined to produce the desired overall effect. The simplest programs contain only one block, known as the program block. All other blocks follow the same basic rules. A block begins with the word "begin" and ends with the word "end".
The focus of this category is on any programming languages using the name of Simula, as well as any versions, dialects, or implementations of the language, as well as any editors, IDEs, or other tools designed to facilitate programming in Simula. Simula user groups, forums, tutorials, or guides are also appropriate for this category.
Recommended Resources
From 1994 to 1998, the University of Montreal used Simula as the basic language to teach programming. Due to a lack of online information about the language, they created this sub-page, offering information about the language and, in particular, links to online resources covering such topics as overviews of the language, bibliographies, language references, Simula software, and other sites offering tutorials or examples of Simula programming, as well as to teaching resources.
http://www.iro.umontreal.ca/~simula/
GitHub: Portable Simula Revisited
Created as an open-source project, the new Simula system was created in response to an idea proposed by James Gosling at the 50th anniversary of Simula in 2017. Written in Java, Portable Simula Revisited compiles to pure Java code, the only exception being that the Goto statement needs to be corrected in the byte code, although this is done automatically. It may be freely downloaded, and several documents define various aspects of the language.
https://portablesimula.github.io/github.io/
GNU Cim is a compiler for the Simula programming language that offers a class concept, separate compilation with full type checking, interface to external C routines, an application package for process simulation, and a coroutine concept. Operating on any GNU or Unix-like operating system, the portability of the GNU Simula Compiler is based on the C programming language. It may be downloaded from the site, and support information is discussed.
https://www.gnu.org/software/cim/
IBM System 360/370 Compiler and Historical Documentation: Simula
Of historical interest, this site is a tribute to Ole-Johan Dahl and Kristen Nygaard, the creators of Simula. It includes an account of the 50th anniversary of the language, as well as a successful project to get the old IBM SIMULA system running on an MVS emulator. Featured are the SIMULA 360 Users Guide, the "Hello World" example, the language standards, and the Simula implementation guide, and links to other Simula informational and resource sites.
http://www.edelweb.eu/Simula/
Hosted by the University of Oslo, the sub-site is dedicated to the Simula programming language, its development, use, and influences. Included are reports of its 50th anniversary, which took place on September 27, 2017, as well as an overview of the various versions of the language, such as Simula I, and the 1968, 1970, 1975, and 1984 versions of Simula 67, and Simula 86. Working compilers are highlighted, and links to other Simula resources are included.
http://folk.uio.no/simula67/
Gunnar Syrrist, the last person in the IBM SIMULA group, when IBM discontinued its development of the language. In order to encourage the continuation of the language, he put up this site, from which a version of PC SIMULA for DOS can be downloaded, which can be run in a DOS window within the Windows platform. Also included is the Programmer's Reference Manual and the SIMULA language Standard, and historical information for the SIMULA Standards Group, the SIMULA Development Group.
http://s120.hbv.no/simula/
Written by Jan Rune Holmevik in 1995, the document represents a comprehensive online account of the Simula programming language's origins and development, originally at the Norwegian Computing Centre in Oslo, by Ole-Johan Dahl and Kristen Nygaard, between 1962 and 1967. In conjunction with its history of the language itself, the paper explores the wider history of the Simula project and its influences.
http://campus.hesge.ch/Daehne/2004-2005/Langages/Simula.htm
The Simula Programming Language
Ted Felix offers a profile of the language, including a review of "Simula Begin," written by G.M. Birtwistle and published in 1973, including the text from the preface of the book and the table of contents. Other resources include links to online resources for Simula programming, by Rob Pooley and Jaroslav Sklenar, and to CIM, a Simula to C translator for Linux, and a collection of Simula classes and other program resources.
http://www.tedfelix.com/software/simula.html
