Computer Languages

The introduction of the compiler in 1952 spurred the development of third-generation computer languages. These languages enable a programmer to create program files using commands that are similar to spoken English. Third-level computer languages have become the major means of communication between the digital computer and its user.

By 1957, the International Business Machine Corporation (IBM) had created a language called FORTRAN (FORmula TRANslater). This language was designed for scientific work involving complicated mathematical formulas. It became the first high-level programming language (or "source code") to be used by many computer users.

Within the next few years, refinements gave rise to ALGOL (ALGOrithmic Language) and COBOL (COmmon Business Oriented Language). COBOL is noteworthy because it improved the record keeping and data management ability of businesses, which stimulated business expansion.

In the early 1960s, scientists at Dartmouth College in New Hampshire developed BASIC (Beginner's All-purpose Symbolic Instruction Code). This was the first widespread computer language designed for and used by nonprofessional programmers. BASIC enjoyed widespread popularity during the 1970s and 1980s, particularly as personal computers grew in use.

Since the 1960s, hundreds of programming languages have been developed. A few noteworthy examples include PASCAL, first developed as a teaching tool; LISP, a language used by computer scientists interested in writing programs they hoped would give computers some abilities usually associated with intelligence in humans; and the C series of programs (i.e., C, C +, C ++). The latter are object-oriented languages, where the object (data) is used by what are known as routines. The C series of programs first allowed a computer to use higher-level language programs like store-bought software.

The actual program written in the third-generation language is called the source program. This is the material that the programmer puts into the computer to obtain results. The source program can usually be translated into an object program (the language of zeros and ones that is interpretable by the computer).

Information in a source program is converted into the object program by an intermediate program called an interpreter or compiler. An interpreter is a program that converts (or executes, in programming jargon) a source program, usually on a step-by-step, line-by-line, or unit-by-unit basis. The price for this convenience is that the programs written in third-generation languages require more memory and run more slowly than those written in lower level languages.

A compiler is a program that translates a source program written in a particular programming language to an object program that a particular computer can run. The compiler is a very specific interpreter, which is both language- and machine-dependent.