ECMA262

ECMA-262 is the standard for the JavaScript programming language, published by ECMA International. It defines the core language syntax and semantics, the built‑in objects and standard library, and the rules by which conforming engines must operate. Implementations such as V8, SpiderMonkey, and JavaScriptCore use ECMA-262 as the reference to ensure interoperability across browsers and other environments.

The standard is maintained by TC39, a technical committee within ECMA International that includes representatives from major browser vendors, runtime developers, and other stakeholders. ECMA-262 evolves through editions released periodically, with proposals to add features reviewed and advanced through a staged process before being included in a future edition. The agreement between editions helps coordinate compatibility and deprecation across engines and platforms.

Historically, the first edition appeared in 1997, with subsequent editions addressing evolving language features. ES5, published in 2009, is often cited as a turning point for better tooling and stricter programming practices. The major modernization known as ES2015 or ES6 was released in 2015, introducing substantial language enhancements. Since then, updates have typically been published annually as ES2016 through ES2023, with ongoing work toward future editions and ongoing refinement of the standard.

ECMA-262 defines ECMAScript, the standardized specification that underpins JavaScript implementations. The standard also includes annexes and normative references that guide interoperability, compatibility, and tooling across different environments, ensuring a consistent baseline for language behavior worldwide.