Think C (stylized as THINK C; formerly Lightspeed C) is an extension of the C programming language for the

classic Mac OS Mac OS (originally System Software; retronym: Classic Mac OS) is the series of operating systems developed for the Macintosh family of personal computers by Apple Computer from 1984 to 2001, starting with System 1 and ending with Mac OS 9. The ...

developed by Think Technologies, released first in mid-1986. THINK was founded by Andrew Singer, Frank Sinton & Mel Conway. The firm was later acquired by Symantec Corporation and the product continued to be developed by the original author, Michael Kahl. Versions 3 and later were essentially a subset of

C++ C++ (pronounced "C plus plus") is a high-level general-purpose programming language created by Danish computer scientist Bjarne Stroustrup as an extension of the C programming language, or "C with Classes". The language has expanded significan ...

and supported basic

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 pr ...

(OOP) concepts such as

single inheritance Multiple inheritance is a feature of some object-oriented computer programming languages in which an object or class can inherit features from more than one parent object or parent class. It is distinct from single inheritance, where an object or ...

, and extensions to the C standard that conformed more closely to the needs of Mac OS programming. After version 6, the OOP facilities were expanded to a full C++

implementation Implementation is the realization of an application, or execution of a plan, idea, model, design, specification, standard, algorithm, or policy. Industry-specific definitions Computer science In computer science, an implementation is a realiza ...

, and the product was rebranded Symantec C++ starting version 7, then under development by different authors. The long-awaited version 8 brought support for compiling to

PowerPC PowerPC (with the backronym Performance Optimization With Enhanced RISC – Performance Computing, sometimes abbreviated as PPC) is a reduced instruction set computer (RISC) instruction set architecture (ISA) created by the 1991 Apple Inc., App ...

. Think C, and later Symantec C++, featured a

class library In computer science, a library is a collection of non-volatile resources used by computer programs, often for software development. These may include configuration data, documentation, help data, message templates, pre-written code and subro ...

and framework for Mac programming called the Think Class Library (TCL), which was used extensively for Macintosh application development. The Lightspeed and Think C

integrated development environment An integrated development environment (IDE) is a software application that provides comprehensive facilities to computer programmers for software development. An IDE normally consists of at least a source code editor, build automation tools a ...

(IDE) influenced other such environments, though considered not as advanced as that belonging to Think Pascal, its sister language product. It was considered the standard environment when

Macintosh Programmer's Workshop Macintosh Programmer's Workshop (MPW) is a software development environment for the Classic Mac OS operating system, written by Apple Computer. For Macintosh developers, it was one of the primary tools for building applications for System 7.x an ...

(MPW) was considered an overpriced niche product, and most Macintosh products were developed in it for many years. This changed with transition of the Mac from the

Motorola 68000 The Motorola 68000 (sometimes shortened to Motorola 68k or m68k and usually pronounced "sixty-eight-thousand") is a 16/32-bit complex instruction set computer (CISC) microprocessor, introduced in 1979 by Motorola Semiconductor Products Sector ...

(68K) to the

central processing unit A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, an ...

(CPU). Symantec was roughly a year late in delivering a version for PowerPC, and was widely seen as having fallen behind, and competitor

Metrowerks Metrowerks was a company that developed software development tools for various desktop, handheld, embedded, and gaming platforms. Its flagship product, CodeWarrior, comprised an IDE, compilers, linkers, debuggers, libraries, and related tools. I ...

' product

CodeWarrior CodeWarrior is an integrated development environment (IDE) published by NXP Semiconductors for editing, compiling, and debugging software for several microcontrollers and microprocessors (Freescale ColdFire, ColdFire+, Kinetis, Qorivva, PX, Free ...

took control of the market. Despite the decline in popularity of their IDE, Symantec was eventually chosen by Apple to provide next-generation C/C++

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 that ...

s for MPW in the form of Sc/Scpp for 68K alongside MrC/MrCpp for PowerPC. These remained Apple's standard compilers until the arrival of

Mac OS X macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac (computer), Mac computers. Within the market of ...

replaced them with the

GNU Compiler Collection The GNU Compiler Collection (GCC) is an optimizing compiler produced by the GNU Project supporting various programming languages, hardware architectures and operating systems. The Free Software Foundation (FSF) distributes GCC as free software ...

(GCC). Symantec subsequently exited the developer tool business.

Reception

Bruce F. Webster Bruce F. Webster is an American academic and software engineer. He is currently a principal at Bruce F. Webster & Associates and an adjunct professor in computer science at Brigham Young University. Early life and education Webster studied ...

of ''

BYTE The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit ...

'' named ''Lightspeed C'' product of the month for September 1986. While criticizing the documentation as its "single greatest weakness", Webster stated that Lightspeed C would be the choice if he had to select one compiler for the Macintosh. ''BYTE'' in 1989 listed Lightspeed C as among the "Distinction" winners of the Byte Awards, stating that it "wins our respect because of its powerful features and low price". ''THINK C 5.0'' obtained in 4 (out 5) rating in July 1992 issue of

Macworld ''Macworld'' is a website dedicated to products and software of Apple Inc., published by Foundry, a subsidiary of IDG Inc. It started life as a print magazine in 1984 and had the largest audited circulation (both total and newsstand) of Macint ...

, praising a fast compilation and an outstanding development environment, despite an insufficient documentation. ''Symantec C++ 8.0'' obtained a 3 (out 5) rating in July 1995 issue of

, comparing favourably the speed of its PowerPC compiled code with that of

at the time, but noting how delayed the product has been and its heavy requirement on resources.

References

{{DEFAULTSORT:Think C 1986 software Integrated development environments Macintosh-only software Classic Mac OS text editors Gen Digital software C (programming language) compilers C++ compilers Classic Mac OS programming tools