This is an accepted version of this page JavaScript (/ˈdʒɑːvəskrɪpt/), often abbreviated as JS, is a programming language and core technology of the World Wide Web, alongside HTML and CSS.

It has application programming interfaces (APIs) for working with text, dates, regular expressions, standard data structures, and the Document Object Model (DOM).

Accessible to non-technical people, it played a prominent role in the rapid growth of the early World Wide Web.

There was a desire in the flourishing web development scene to remove this limitation, so in 1995, Netscape decided to add a programming language to Navigator.

[5][6] Although the new language and its interpreter implementation were called LiveScript when first shipped as part of a Navigator beta in September 1995, the name was changed to JavaScript for the official release in December.

At the time, the dot-com boom had begun and Java was a popular new language, so Eich considered the JavaScript name a marketing ploy by Netscape.

"[14] In November 1996, Netscape submitted JavaScript to Ecma International, as the starting point for a standard specification that all browser vendors could conform to.

[18] However, the effort to fully standardize the language was undermined by Microsoft gaining an increasingly dominant position in the browser market.

Microsoft initially participated in the standards process and implemented some proposals in its JScript language, but eventually it stopped collaborating on ECMA work.

This led to Mozilla working jointly with Macromedia (later acquired by Adobe Systems), who were implementing E4X in their ActionScript 3 language, which was based on an ECMAScript 4 draft.

In 2005, Jesse James Garrett released a white paper in which he coined the term Ajax and described a set of technologies, of which JavaScript was the backbone, to create web applications where data can be loaded in the background, avoiding the need for full page reloads.

Ambitious work on the language continued for several years, culminating in an extensive collection of additions and refinements being formalized with the publication of ECMAScript 6 in 2015.

Node combines the V8 engine, an event loop, and I/O APIs, thereby providing a stand-alone JavaScript runtime system.

[32] The ECMAScript draft specification is currently maintained openly on GitHub,[33] and editions are produced via regular annual snapshots.

Initial attempts at promoting server-side JavaScript usage were Netscape Enterprise Server and Microsoft's Internet Information Services,[45][46] but they were small niches.

Other non-browser applications include Adobe Acrobat support for scripting PDF documents[48] and GNOME Shell extensions written in JavaScript.

The runtime system includes the necessary APIs for input/output operations, such as networking, storage, and graphics, and provides the ability to import scripts.

[66] Additionally, ECMAScript version 6 (released June 2015) introduced the keywords class, extends and super, which serve as syntactic sugar to abstract the underlying prototypal inheritance system with a more conventional interface.

Private variables are declared by prefixing the field name with a hashtag (#), and polymorphism is not directly supported, although it can be emulated by manually calling different functions depending on the number and type of arguments provided.

A Role then has to be delegated explicitly via call or apply to objects that need to feature additional behavior that is not shared via the prototype chain.

In a manner similar to Perl, JavaScript also supports regular expressions, which provide a concise and powerful syntax for text manipulation that is more sophisticated than the built-in string functions.

Arrow functions are anonymous, so a variable is needed to refer to them in order to invoke them after their creation, unless surrounded by parenthesis and executed immediately.

JavaScript and the DOM provide the potential for malicious authors to deliver scripts to run on a client computer via the Web.

[85] Content Security Policy is the main intended method of ensuring that only trusted code is executed on a Web page.

Possible solutions include: Developers of client-server applications must recognize that untrusted clients may be under the control of attackers.

For example, a buffer overrun exploit can allow an attacker to gain access to the operating system's API with superuser privileges.

[95][96] In Windows Vista, Microsoft has attempted to contain the risks of bugs such as buffer overflows by running the Internet Explorer process with limited privileges.

Incorrectly granting privileges to JavaScript from the Web has played a role in vulnerabilities in both Internet Explorer[98] and Firefox.

[111] Both languages first appeared in 1995, but Java was developed by James Gosling of Sun Microsystems and JavaScript by Brendan Eich of Netscape Communications.

WebAssembly is a newer language with a bytecode format designed to complement JavaScript, especially the performance-critical portions of web page scripts.