Pascal

Pascal is a powerful, general-purpose programming language in which data and algorithms can be expressed clearly. Pascal's strong typing catches many errors at compile time rather than run time--consequently saving the programmer time and effort, and making code more reliable. Professional programmers who frequently use Pascal as well as the more common C, C++ or Java languages often report that they can develop and maintain code more quickly and with fewer errors when they work in Pascal. (Programmers who have significant experience in only one language always find that language to be the best and most beautiful.)

A brief history: Niklaus Wirth drafted a preliminary description of the programming language Pascal in 1968, drawing heavily on Algol-60, but with major extensions in data structures. The first compiler, by Urs Ammann, was operational in 1970, and the first published language description was 1971 (N. Wirth, The Programming Language Pascal, Acta Informatica 1: 35-63, also in Programming Language Design, A.I.Wasserman, Ed., IEEE Computer Society Press, 1980 ). Hundreds of implementations followed, by 1980, for almost every known computer. But progress was slow on developing a standard for Pascal extensions important for large-scale systems programming (eventually published as Extended Pascal). At the same time, other languages expanded or emerged: C was carried along with the rise of UNIX, C++ spread because it was first with object-oriented features, and Java due to its orientation for web programming. Today, although it is no longer the most prevalent language, Pascal and especially Extended Pascal offer many advantages over other programming languages, whether as a first language for a student or as the language of a team of professionals programing large, mission-critical software.

Standards

Classic Standard Pascal A 1974 book by Kathleen Jensen and Niklaus Wirth, Pascal User Manual and Report (Springer-Verlag) served for years as the only definition of the language (Jensen was subsequently updated; see below). Because of the popularity of Pascal, a more precise definition was developed by the International Standards Organization (ISO), along with IEEE, ANSI and BSI. The resulting document for "Standard Pascal" is available in PDF here as a free download:

Although precise, the official definition is very hard to read. It may be tempting to read the above standard document because it is a free download, if you are starting out with Pascal it will almost certainly be unreadable. (And we don't mean "hard to read", we mean "unreadable.") Two excellent, highly readable versions of the ISO Pascal standard have been published:

Doug Cooper, 1983, Standard Pascal User Reference Manual (W.W. Norton and Company, ISBN: 0393301214).

Kathleen Jensen, Niklaus Wirth, Andrew B. Mickel, and James F. Miner, 1985 Pascal, User Manual and Report, 3rd Edition 1985, 4th Edition 1991 (Springer Verlag, ISBN: 0387976493).

Get the book by Cooper, the one by Jensen, Wirth, Mickel and Miner, or a good Pascal textbook. Both the above are available from Amizon.com in 2002 (yes, some books are expensive; remember, books are free in the library).

Extended Pascal To define a fully-functional language for large commercial use, while retaining the solid structure and typing of Standard Pascal, a definition of "Extended Pascal" has been developed. The official standard, again from ISO, is available here, as is the set of Object-Oriented extensions proposed by the Extended Pascal committee:

Again, the official standard is difficult to read. Tony Hetherington at Prospero Software, which provides an Extended Pascal compiler has written two highly readable descriptions.

Hetherington has a short web-readable introduction to Extended Pascal, in terms of its extensions from "classic" Standard Pascal. This can be seen by clicking on: Extended Pascal ... a new standard in computer languages (HTML). by Tony Hetherington, 1993, Prospero Software Ltd.

A printed, still highly readable but more complete description of Extended Pascal, with its object extensions, is: Extended Pascal and Objects: A Practical Guide, by Tony Hetherington, 1996, Prospero Software Ltd. London. 59 pp. To request a printed copy, click on the link to Prospero Software.

Finally, a set of questions and answers by John Reagan about Pascal and Pascal standards, can be viewed here as an HTML file:
  Pascal Standards FAQ (HTML).