Clascal is an

object-oriented programming Object-oriented programming (OOP) is a programming paradigm based on the concept of "objects", which can contain data and code. The data is in the form of fields (often known as attributes or ''properties''), and the code is in the form of ...

language (and associated discontinued

compiler In computing, a compiler is a computer program that translates computer code written in one programming language (the ''source'' language) into another language (the ''target'' language). The name "compiler" is primarily used for programs tha ...

) developed in 1983 by the ''Personal Office Systems'' (POS) division (later renamed ''The Lisa Division'', then later ''The 32-Bit Systems Division'') of

Apple Computer Apple Inc. is an American multinational technology company headquartered in Cupertino, California, United States. Apple is the largest technology company by revenue (totaling in 2021) and, as of June 2022, is the world's biggest company ...

. Clascal was used to program applications for the ''Lisa Office System'', the operating environment of the Lisa. According to Larry Tesler, this was developed as a replacement for their version of

Smalltalk Smalltalk is an object-oriented, dynamically typed reflective programming language. It was designed and created in part for educational use, specifically for constructionist learning, at the Learning Research Group (LRG) of Xerox PARC by Alan ...

that was too slow. It was an extension of Lisa

Pascal Pascal, Pascal's or PASCAL may refer to: People and fictional characters * Pascal (given name), including a list of people with the name * Pascal (surname), including a list of people and fictional characters with the name ** Blaise Pascal, Frenc ...

, which in turn harked back to the

UCSD Pascal UCSD Pascal is a Pascal programming language system that runs on the UCSD p-System, a portable, highly machine-independent operating system. UCSD Pascal was first released in 1977. It was developed at the University of California, San Diego (U ...

model originally implemented on the

Apple II The Apple II (stylized as ) is an 8-bit home computer and one of the world's first highly successful mass-produced microcomputer products. It was designed primarily by Steve Wozniak; Jerry Manock developed the design of Apple II's foam-m ...

. It was strongly influenced by the Xerox Palo Alto Research Center ( PARC) release of

-80, v1 (which had been formerly ported to the Lisa), and by

Modula The Modula programming language is a descendant of the Pascal language. It was developed in Switzerland, at ETH Zurich, in the mid-1970s by Niklaus Wirth, the same person who designed Pascal. The main innovation of Modula over Pascal is a modul ...

. Clascal was the base for

Object Pascal Object Pascal is an extension to the programming language Pascal that provides object-oriented programming (OOP) features such as classes and methods. The language was originally developed by Apple Computer as ''Clascal'' for the Lisa Worksh ...

on the Apple

Macintosh The Mac (known as Macintosh until 1999) is a family of personal computers designed and marketed by Apple Inc., Apple Inc. Macs are known for their ease of use and minimalist designs, and are popular among students, creative professionals, and ...

in 1985. With the demise of the Lisa in 1986, Pascal and Object Pascal continued to be used in the Macintosh Programmer's Workshop for systems and application development for several more years, until it was finally supplanted by the languages C and C++. The MacApp application framework was based on ''Toolkit'' originally written in Clascal. Ultimately Object Pascal evolved into the language of

Borland Borland Software Corporation was a computer technology company founded in 1983 by Niels Jensen, Ole Henriksen, Mogens Glad and Philippe Kahn. Its main business was the development and sale of software development and software deployment product ...

Delphi Delphi (; ), in legend previously called Pytho (Πυθώ), in ancient times was a sacred precinct that served as the seat of Pythia, the major oracle who was consulted about important decisions throughout the ancient classical world. The orac ...

References

* Programming languages Pascal programming language family Class-based programming languages Object-oriented programming languages High-level programming languages Programming languages created in 1983 {{Prog-lang-stub