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In computer science, Modula-3 is a programming language conceived as a successor to an upgraded version of Modula-2 known as Modula-2+. While it has been influential in research circles (influencing the designs of languages such as Java, C#, and Python) it has not been adopted widely in industry. It was designed by Luca Cardelli, James Donahue, Lucille Glassman, Mick Jordan (before at the Olivetti Software Technology Laboratory), Bill Kalsow and Greg Nelson at the Digital Equipment Corporation (DEC) Systems Research Center (SRC) and the Olivetti Research Center (ORC) in the late 1980s. Modula-3's main features are simplicity and safety while preserving the power of a systems-programming language. Modula-3 aimed to continue the Pascal tradition of type safety, while introducing new constructs for practical real-world programming. In particular Modula-3 added support for generic programming (similar to templates), multithreading, exception handling, garbage collection, object-oriented programming, partial revelation and explicit mark of unsafe code. The design goal of Modula-3 was a language that implements the most important features of modern imperative languages in quite basic forms. Thus allegedly dangerous and complicating features like multiple inheritance and operator overloading were omitted. ==Historical development== The Modula-3 project started in November 1986 when Maurice Wilkes wrote to Niklaus Wirth with some ideas for a new version of Modula. Wilkes had been working at DEC just prior to this point, and had returned to England and joined Olivetti's Research Strategy Board. Wirth had already moved on to Oberon, but had no problems with Wilkes's team continuing development under the Modula name. The language definition was completed in August 1988, and an updated version in January 1989. Compilers from DEC and Olivetti soon followed, and 3rd party implementations after that. Its design was heavily influenced by work on the Modula-2+ language in use at SRC and at the Acorn Computers Research Center (ARC, later ORC when Olivetti bought out Acorn) at the time, which was the language in which the operating system for the DEC Firefly multiprocessor VAX workstation was written and in which the Acorn Compiler for Acorn C and Modula Execution Library (CAMEL) at ARC for the ARX operating system project of ARM based Acorn Archimedes range of computers was written. As the revised Modula-3 Report states, the language was influenced by other languages such as Mesa, Cedar, Object Pascal, Oberon and Euclid.〔(Modula-3 report (revised) ) Luca Cardelli, James Donahue, Lucille Glassman, Mick Jordan, Bill Kalsow, Greg Nelson. DEC Systems Research Center (SRC) Research Report 52 (November 1989)〕 During the 1990s, Modula-3 gained considerable currency as a teaching language, but it was never widely adopted for industrial use. Contributing to this may have been the demise of DEC, a key Modula-3 supporter (specially when it ceased to maintain it effectively any more before DEC was sold to Compaq in 1998). In any case, in spite of Modula-3's simplicity and power, it appears that there was little demand for a procedural compiled language with restricted implementation of object-oriented programming. For a time, a commercial compiler called CM3 maintained by one of the chief implementors prior at DEC SRC who was hired before DEC being sold to Compaq, an integrated development environment called Reactor and an extensible Java Virtual Machine (licensed in binary and source formats and buildable with Reactor) were offered by Critical Mass, Inc., but that company ceased active operations in 2000 and gave some of the sources of its products to elego Software Solutions GmbH. Modula-3 is now taught in universities mostly in comparative programming language courses, and its textbooks are out of print. Essentially the only corporate supporter of Modula-3 is elego Software Solutions GmbH, which inherited the sources from Critical Mass and has since made several releases of the CM3 system in source and binary form. The Reactor IDE has been open source released after several years it had not, with the new name CM3-IDE. In March 2002 elego also took over the repository of another active Modula-3 distribution, PM3, till then maintained at the École Polytechnique de Montréal but which later continued by the work on HM3 improved over the years later until it was obsoleted. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Modula-3」の詳細全文を読む スポンサード リンク
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