History of Programming Languages

History of Programming Languages

To date, there have been two conferences focusing on programming languages. The Special Interest Group on Programming Languages (SIGPLAN) of the Association for Computing Machinery sponsored two "History of Programming Languages (HOPL)" conferences. The first of these took place in Los Angeles in 1978, and focused on thirteen early languages: ALGOL, APL, APT, BASIC, COBOL, FORTRAN, GPSS, JOSS, JOVIAL, LISP, PL/I, SIMULA, and SNOBOL. The prospectus for the first HOPL conferences stipulated that to be considered, the languages had to have been "created and in use by 1967, remain in use in 1977, and had a considerable influence on the field of computing."

The second HOPL conference took place in Cambridge, MA in 1994, and focused on fourteen later languages: Ada, ALGOL 68, C, C++, Discrete Simulation Languages, FORMAC, Forth, Icon, Lisp, Monitors and concurrent Pascal, Pascal, Prolog, and Smalltalk. The prospectus for the second HOPL conference stipulated that to be considered "preliminary ideas about the language [should have been] documented by 1982 and the language .. in use or being taught by 1985."

Although the Program Committees of the respective HOPL conferences did an excellent job of encouraging authors and editing material, many languages had to be excluded due to the time constraints of a three day conference. Thus, there is a pressing need to capture information and materials on languages which were not represented at these conferences.

Existing analyses of the history of early programming languages show most to be the work of individuals (APL, Pascal, C++), with some notable exceptions (Ada, COBOL, and ALGOL). At the present time, we see numerous languages in widespread use such as Java, Visual C++ and Visual Basic, which are the products of corporate efforts, and thus have multiple "developers". Since the use of these "object-oriented and visual" languages is growing at a tremendous rate, capturing their evolution and history is imperative. This page seeks to provide a place and a process where interested individuals and groups can discuss their expereiences as developers and users of specific programming languages.

History of Visual Programming Languages

The field of visual programming has grown from a marriage of work in computer graphics, programming languages, and human-computer interaction. It should come as no surprise, then, that much of the seminal work in the field is also viewed as pioneering work in one of the other disciplines. Ivan Sutherland's groundbreaking Sketchpad system stands out as the best example of this trend [Sutherland 1963]. Sketchpad, designed in 1963 on the TX-2 computer at MIT, has been called the first computer graphics application. The system allowed users to work with a lightpen to create 2D graphics by creating simple primitives, like lines and circles, and then applying operations, such as copy, and constraints on the geometry of the shapes. Its graphical interface and support for user-specifiable constraints stand out as Sketchpad's most important contributions to visual programming languages. By defining appropriate constraints, users could develop structures such as complicated mechanical linkages and then move them about in real time. We will see the idea of visually specified constraints and constraint-oriented programming resurface in a number of later VPLs. Ivan Sutherland's brother, William, also made an important early contribution to visual programming in 1965, when he used the TX-2 to develop a simple visual dataflow language. The system allowed users to create, debug, and execute dataflow diagrams in a unified visual environment [Najork 1995].

The next major milestone in the genesis of VPLs came in 1975 with the publication of David Canfield Smith's PhD dissertation entitled ''Pygmalion: A Creative Programming Environment'' [Smith 1975]. Smith's work marks the starting point for a number of threads of research in the field which continue to this day. For example, Pygmalion embodied an icon-based programming paradigm in which the user created, modified, and linked together small pictorial objects, called icons, with defined properties to perform computations. Much work has since gone into formalizing icon theory, as will be discussed below, and many modern VPLs employ an icon-based approach. Pygmalion also made use of the concept of programming-by-example wherein the user shows the system how to perform a task in a specific case and the system uses this information to generate a program which performs the task in general cases. In Smith's system, the user sets the environment to ''remember'' mode, performs the computation of interest, turns