Editing Pascal (programming language) (section)

==History==
===Earlier efforts===
Much of the history of [[computer language]] design during the 1960s can be traced to the [[ALGOL 60]] language. ALGOL was developed during the 1950s with the explicit goal of being able to clearly describe [[algorithm]]s. It included a number of features for [[structured programming]] that remain common in languages to this day.

Shortly after its introduction, in 1962 Wirth began working on his dissertation with Helmut Weber on the [[Euler (programming language)|Euler programming language]]. Euler was based on ALGOL's syntax and many concepts but was not a derivative. Its primary goal was to add dynamic lists and types, allowing it to be used in roles similar to [[Lisp (programming language)|Lisp]]. The language was published in 1965.

By this time, a number of problems in ALGOL had been identified, notably the lack of a standardized [[String (computer science)|string]] system. The group tasked with maintaining the language had begun the [[ALGOL X]] process to identify improvements, calling for submissions. Wirth and [[Tony Hoare]] submitted a conservative set of modifications to add strings and clean up some of the syntax. These were considered too minor to be worth using as the new standard ALGOL, so Wirth wrote a compiler for the language, which became named [[ALGOL W]].

The ALGOL X efforts would go on to choose a much more complex language, [[ALGOL 68]]. The complexity of this language led to considerable difficulty producing high-performance compilers, and it was not widely used in the industry. This left an opening for newer languages.

===Pascal===
Pascal was influenced by the ALGOL W efforts, with the explicit goals of teaching programming in a [[structured programming|structured fashion]] and for the development of system software.<ref>{{Cite book|chapter-url=https://link.springer.com/chapter/10.1007/10722581_1|doi = 10.1007/10722581_1|chapter = The Development of Procedural Programming Languages Personal Contributions and Perspectives|title = Modular Programming Languages|series = Lecture Notes in Computer Science|year = 2000|last1 = Wirth|first1 = Niklaus|volume = 1897|pages = 1–10|isbn = 978-3-540-67958-5}}</ref> A generation of students used Pascal as an introductory language in undergraduate courses. Other goals included providing a reliable and efficient tool for writing large programs,<ref>{{cite journal |last1=Wirth |first1=N. |title=The Programming Language Pascal |journal=Acta Informatica |date=1971 |volume=1 |issue=1 |pages=35–63 |doi=10.1007/BF00264291|hdl=20.500.11850/68712 |hdl-access=free }}</ref> and bridging the canyon between scientific and commercial programming, as represented by the then-widespread languages Fortran and COBOL, with a general-purpose language.<ref>{{cite book |last1=Wirth |first1=N. |chapter=Recollections about the development of Pascal |title=History of programming languages---II |date=January 1996 |pages=97–120 |doi=10.1145/234286.1057812|isbn=0-201-89502-1 }}</ref>

One of the early successes for the language was the introduction of [[UCSD Pascal]], a version that ran on a custom [[operating system]] that could be ported to different platforms. A key platform was the [[Apple II]], where it saw widespread use as [[Apple Pascal]]. This led to Pascal becoming the primary [[high-level language]] used for development in the [[Apple Lisa]], and later, the [[Mac (computer)|Macintosh]]. Parts of the original [[Classic Mac OS|Macintosh operating system]] were hand-translated into [[Motorola 68000]] [[assembly language]] from the Pascal [[source code]].<ref>Hertzfeld, Andy. "[http://www.folklore.org/StoryView.py?project=Macintosh&story=Hungarian.txt&topic=Software%20Design&sortOrder=Sort%20by%20Date&detail=medium Hungarian folklore.org] {{webarchive|url=https://web.archive.org/web/20151118082558/http://www.folklore.org/StoryView.py?project=Macintosh&story=Hungarian.txt&topic=Software%20Design&sortOrder=Sort%20by%20Date&detail=medium |date=2015-11-18}}: Macintosh Stories. Retrieved 2012-03-06.</ref>

The [[typesetting]] system [[TeX]] by [[Donald Knuth]] was written in [[WEB]], the original [[literate programming]] system, based on [[Digital Equipment Corporation|DEC]] [[PDP-10]] Pascal. Successful commercial applications like [[Adobe Photoshop]]<ref>https://www.computerhistory.org/atchm/adobe-photoshop-source-code/ {{Webarchive|url=https://web.archive.org/web/20140507131754/http://www.computerhistory.org/atchm/adobe-photoshop-source-code/ |date=2014-05-07}}, Adobe Photoshop Source Code</ref> were written in [[Macintosh Programmer's Workshop]] Pascal, while applications like [[Total Commander]], [[Skype]]<ref>{{cite web |url=https://www.embarcadero.com/products/rad-studio/application-showcase|title=RAD Studio Application Showcase|date=2021-10-29}}</ref> and [[Macromedia Captivate]] were written in Delphi ([[Object Pascal]]). [[Apollo Computer]] used Pascal as the systems programming language for its operating systems beginning in 1980.

Variants of Pascal have also been used for everything from research projects to [[PC game]]s and [[embedded system]]s. Newer Pascal compilers exist which are widely used.<ref>[http://www.tiobe.com/index.php/content/paperinfo/tpci/ tiobe.com] {{webarchive|url=https://web.archive.org/web/20120315012717/http://www.tiobe.com/index.php/content/paperinfo/tpci |date=2012-03-15}}, Programming Community Index for January 2011.</ref>

===Dialects===
Wirth's example compiler meant to propagate the language, the Pascal-P system, used a subset of the language designed to be the minimal subset of the language that could compile itself. The idea was that this could allow bootstrapping the compiler, which would then be extended to full Pascal language status. This was done with several compilers, but one notable exception was UCSD Pascal, which was based on Pascal-P2. It kept the subset status of the language based on the idea that this would run better on the new (then) microprocessors with limited memory. UCSD also converted the Pascal-P2 interpreter into a "byte machine", again, because it would be a better fit for byte oriented microprocessors.

UCSD Pascal formed the basis of many systems, including Apple Pascal. Borland Pascal was not based on the UCSD codebase, but arrived during the popular period of UCSD and matched many of its features. This started the line that ended with Delphi Pascal and the compatible Open Source compiler FPC/Lazarus.

The ISO standard for Pascal, ISO 7185, was published in 1983 and was widely implemented and used on mainframes, minicomputers and IBM-PCs and compatibles from 16 bits to 32 bits. The two dialects of Pascal most in use towards the end of the 20th century and up until today are the ISO 7185 standard version and the Delphi/Turbo Pascal versions (of which the two Borland versions are mostly compatible with each other).

The source for much of the early history on Pascal can be found in the Pascal User's Group newsletters at:

[https://www.standardpascal.org/pug.html Pascal Users Group Newsletters].

===Object Pascal===
During work on the Lisa, [[Larry Tesler]] began corresponding with Wirth on the idea of adding object-oriented extensions to the language, to make Pascal a [[Programming paradigm|multi-paradigm programming language]]. This led initially to [[Clascal]], introduced in 1983. As the Lisa program faded and was replaced by the Macintosh, a further version was created and named [[Object Pascal]]. This was introduced on the Mac in 1985 as part of the [[MacApp]] [[application framework]], and became Apple's main development language into the early 1990s.

The Object Pascal extensions were added to [[Turbo Pascal]] with the release of version 5.5 in 1989.<ref>{{cite web|title=Antique Software: Turbo Pascal v5.5|url=http://edn.embarcadero.com/article/20803|access-date=2018-05-17|archive-date=2010-11-24|archive-url=https://web.archive.org/web/20101124090934/http://edn.embarcadero.com/article/20803|url-status=dead}}</ref> Over the years, Object Pascal became the basis of the [[Delphi (software)|Delphi]] system for [[Microsoft Windows]], which is still used for developing Windows applications, and can [[cross-compile]] code to other systems. [[Free Pascal]] is an open source, cross-platform alternative with its own graphical [[integrated development environment|IDE]] called [[Lazarus (IDE)|Lazarus]].