JavaScript is a programming language. Its formal name is ECMAScript, and its official definition is the standard ECMA-262 of Ecma International, a standards organization. The committee TC39 (Technical Committee 39), a group of JavaScript developers, implementers and academics, maintains and changes this definition. TC39 writes the specification on GitHub, meets every two months, and moves each proposed language feature through numbered stages; a feature at Stage 3 is close to completion.
JavaScript is best known as the scripting language of web pages, and it also runs outside the browser, for example on servers with Node.js. It is a dynamic language (types are checked while the program runs, not before), garbage-collected (unused memory is freed automatically) and prototype-based (objects inherit directly from other objects). It supports imperative, functional and object-oriented styles.
The language is an open standard, not a product. A new edition of ECMA-262 has appeared every June since the 6th edition of 2015; the 17th edition, ECMAScript 2026, appeared in June 2026 under Ecma's royalty-free patent policy.