The 1950s and 1960s
In the 1950s, the first three modern programming languages whose descendants are still in widespread use today were designed:
- FORTRAN (1955), the "FORmula TRANslator", invented by John Backus et al.;
- LISP (1958), the "LISt Processor", invented by John McCarthy et al.;
- COBOL,(1959) the COmmon Business Oriented Language, created by the Short Range Committee, heavily influenced by Grace Hopper.
Another milestone in the late 1950s was the publication, by a committee of American and European computer scientists, of "a new language for algorithms"; the ALGOL 60 Report (the "ALGOrithmic Language"). This report consolidated many ideas circulating at the time and featured two key language innovations:
- nested block structure: code sequences and associated declarations could be grouped into blocks without having to be turned into separate, explicitly named procedures;
- lexical scoping: a block could have its own private variables, procedures and functions, invisible to code outside that block, i.e. information hiding.
Another innovation, related to this, was in how the language was described:
- a mathematically exact notation, Backus-Naur Form (BNF), was used to describe the language's syntax. Nearly all subsequent programming languages have used a variant of BNF to describe the context-free portion of their syntax.
Algol 60 was particularly influential in the design of later languages, some of which soon became more popular. The Burroughs large systems were designed to be programmed in an extended subset of Algol.
Algol's key ideas were continued, producing ALGOL 68:
- syntax and semantics became even more orthogonal, with anonymous routines, a recursive typing system with higher-order functions, etc.;
- not only the context-free part, but the full language syntax and semantics were defined formally, in terms of Van Wijngaarden grammar, a formalism designed specifically for this purpose.
Algol 68's many little-used language features (e.g. concurrent and parallel blocks) and its complex system of syntactic shortcuts and automatic type coercions made it unpopular with implementers and gained it a reputation of being difficult. Niklaus Wirth actually walked out of the design committee to create the simpler Pascal language.
Some important languages that were developed in this period include:
- 1951 - Regional Assembly Language
- 1952 - Autocode
- 1954 - IPL (forerunner to LISP)
- 1955 - FLOW-MATIC (forerunner to COBOL)
- 1957 - FORTRAN (First compiler)
- 1957 - COMTRAN (forerunner to COBOL)
- 1958 - LISP
- 1958 - ALGOL 58
- 1959 - FACT (forerunner to COBOL)
- 1959 - COBOL
- 1959 - RPG
- 1962 - APL
- 1962 - Simula
- 1962 - SNOBOL
- 1963 - CPL (forerunner to C)
- 1964 - BASIC
- 1964 - PL/I
- 1967 - BCPL (forerunner to C)
Read more about this topic: History Of Programming Languages