JavaScript (JS) is a programming language mostly used client-side to dynamically script webpages, but often also server-side.
JavaScript is not closely related to Java, but see here for a comparison.
Conceived as a server-side language by Brendan Eich (a then-employee of Netscape Corporation), JavaScript soon came to Netscape Navigator 2.0 in September 1995. JavaScript enjoyed immediate success and Internet Explorer 3.0 introduced JavaScript support under the name JScript in August 1996.
In November 1996, Netscape began working with ECMA International to make JavaScript an industry standard. Since then, the standardized JavaScript is called ECMAScript and specified under ECMA-262, whose latest (seventh) edition is available in June 2016.
JavaScript is mostly used in the browser, enabling developers to manipulate webpage content through the DOM, manipulate data with AJAX and IndexedDB, draw graphics with canvas, interact with the device running the browser through various APIs, and so on. JavaScript is one of the world's most used languages, owing to the recent growth and performance improvement of APIs available in browsers.
Recently, JavaScript came back to the server with the successful Node.js platform, the most popular cross-platform JavaScript runtime environment outside the browser. Node.js allows you to use JavaScript as a scripting language to automate things on a PC and build fully functional HTTP and Web Sockets servers.
Learn more
General knowledge
- JavaScript on Wikipedia
Learning JavaScript
- The JavaScript Guide on MDN
- The "javascripting" workshop on NodeSchool
- The JavaScript course on codecademy.com
- John Resig's Learning Advanced JavaScript