From LQWiki

Pascal is an imperative computer programming language, developed in 1970 by Niklaus Wirth as a language particularly suitable for structured programming.

Pascal is based on the ALGOL programming language and named in honor of mathematician and philosopher Blaise Pascal. Wirth also developed Modula-2 and Oberon, languages similar to Pascal. Oberon also supports object-oriented programming.

Initially, Pascal was a language intended to teach students structured programming, and generations of students have "cut their teeth" on Pascal as an introductory language in undergraduate courses. Variants of Pascal are still widely used today, both in education and software development.

Much of the original Macintosh operating system was written in Pascal. The popular typesetting system TeX is written in a language named WEB for which Donald Knuth borrowed heavily from Pascal.

History

In the 1980s Anders Hejlsberg wrote the Blue Label Pascal compiler for the Nascom-2. Later he went to work for Borland and rewrote his compiler to become Turbo Pascal for the IBM PC. This new compiler sold for $49.95, which was much less than the price Hejlsberg originally asked for the Blue Label Pascal compiler.

The inexpensive Borland compiler had a large influence on the Pascal community that began concentrating mainly on the IBM PC in the late 1980s. Many PC hobbyists in search of a structured replacement for BASIC used this product.

Super Pascal was a variant which added non-numeric labels, a return statement and expressions as names of types.

With Turbo Pascal version 5.5 Borland added object orientation to Pascal.

However, Borland later decided it wanted more elaborate object-oriented features, and started over in Delphi using the Object Pascal draft standard proposed by Apple as a basis. (This Apple draft is still not a formal standard.) Borland also called this Object Pascal in the first Delphi versions, but changed the name to Delphi programming language in later versions. The main additions compared to the older OOP extensions were a reference-based object model, virtual constructors and destructors, and properties. There are several other compilers implementing this dialect: see Delphi programming language.

Turbo Pascal, and other derivatives with units or module concepts are modular languages. Turbo Pascal copied these concepts from either a draft of the Extended Pascal standard or Pascal's successor Modula-2. However, it does not provide a nested module concept or qualified import and export of specific symbols.

Pascal and Linux

There are three main Pascal compilers for Linux:

• Free Pascal
• GNU Pascal
• Kylix

Famous softwares written in pascal that runs on Linux:

• Skype

External links

• Lazarus (www.lazarus.freepascal.org)

  is a cross platform Visual RAD IDE. Lazarus uses Free Pascal complier.

• Free Pascal (en.wikipedia.org)

  is written in Pascal (so that it compiles itself), and is aimed at providing a convenient and powerful compiler, able both to compile legacy applications and to be the means of develop new ones. Also distributed freely under the GNU GPL. It can mix Turbo Pascal with Delphi code, and supports a lot of platforms and operating systems.