ECMAScript

ECMAScript is a Computer programming language of the type script developed within the framework of work of ECMA. It is thus about a standard whose specifications are implemented in the majority of the languages script, like JavaScript or ActionScript. The last specifications, under development, make of it true a Computer programming language directed object.

History and Development

LiveScript and Mosaic Communications Corporation

The company Netscape, at the origin known under the name of Mosaic Communications Corporation, developed a language of script side waiter, called LiveScript, to reinforce the commercial offer of its Web server. The exit of LiveScript intervened at the time where NCSA force Mosaic Communications Corporation to change name to become Netscape.

Netscape then worked with the development of a directed version customer of LiveScript. A few days before its exit, Netscape changed the name of LiveScript for JavaScript. Sun Microsystems and Netscape was partners, and the virtual machine increasingly popular Java. This name change served the interests of the two companies, and Sun promised not to continue Netscape.

Javascript and Netscape

In December 1995, Sun and Netscape announce (in) the exit of JavaScript. In March 1996, Netscape implements the engine Javascript in its navigator Web Netscape Navigator 2.0. The success of this navigator contributes to the fast adoption of Javascript in the development Web directed customer. Microsoft reacts then by developing JScript, that it included then in Internet Explorer 3.0 in August 1996 for the exit of its navigator.

Netscape then subjects JavaScript to ECMA for standardization. Work begins in November 1996, and finishes in June 1997 by the adoption of the new standard ECMAScript . The specifications are written in the document Standard ECMA-262 .

Versions

ECMA-262

There exist to date 3 versions of standard ECMA-262.

ECMAScript Edition 4

Fourth under development, and is often named ECMAScript Edition 4 .

Comparative

E4X

ECMAScript for XML (E4X) is an extension XML to the ECMAScript language. It is indeed a different standard: ECMA-357 (in).

Denomination

Note (1): E4X partly supported by Gecko 1.8.1; for other functionalities, to see Innovations in Javascript 1.7.

Note (2): Microsoft indicates that JScript 8.0 supports “almost all the characteristics of ECMAScript Edition 3" but does not give list of the not supported characteristics.

Note (3): In addition to the support of ECMA-262 edition 3, ActionScript 2 also included a support of the properties, functions and mechanism which had been proposes in a preliminary version of ECMA-262 edition 3. It is not known if ActionScript will remain synchronized with future modifications of the specifications of ECMAScript.

Note (4): Adobe indicates to support a preliminary version of edition 4 of ECMA-262

Note (5): OpenLaszlo supports ECMA-262 edition 3 partially

The support by Mozilla, (SpiderMonkey in language C and Rhino in Java), are used by several third program, for example the Yahoo! Widget Engine (Konfabulator) and the language of script for Macintosh JavaScript DARED.

Safari uses JavaScriptCore which is based on the bookseller KJS of KDE.

Correspondence

ECMAScript Edition 4 (ES4)

The first work was criticized because they modified the nature of the language, which passed from a model of programming with the prototype towards a traditional model based on the classes like Java or C#.

This model directed prototype is for much the most powerful model under development directed object.

A first version of the reference frame of implementation of ECMAScript 4 is available since June 2007.

In addition, Mozilla and Adobe Systems work since months with the implementation of the specifications of ECMAScript 4 in JavaScript 2 and ActionScript 3. To reconcile these implémentaions with the creation of the virtual machine Tamarin, Mozilla and Adobe Systems collaborates on the project Tamarin.

Appendices

Notes & references

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