ECMAScript is the standardised specification of the scripting language commonly implemented as JavaScript, defining its syntax, semantics, and core libraries. Maintained by Ecma International as the ECMA-262 standard and developed through the TC39 process, it provides a stable, versioned contract that browser and runtime vendors implement. ECMAScript underpins client-side web programming and a large ecosystem of server-side and tooling runtimes.
Overview
- ECMAScript defines the language contract that JavaScript engines implement.
- It evolves through the TC39 committee and annual versioned editions.
- Standardisation lets multiple independent runtimes interoperate predictably.
- It is the lingua franca of the browser and a major server-side runtime language.
Key aspects
- A formal specification (ECMA-262) defines syntax, semantics, and built-in objects.
- The TC39 staged proposal process governs how features mature into the standard.
- Versioned annual editions provide a predictable upgrade cadence.
- Conformance test suites verify that engine implementations match the specification.
Applications
- Client-side logic for interactive web applications.
- Server-side runtimes for back-end services and tooling.
- Build and automation scripting across the developer toolchain.
- Cross-platform application frameworks targeting multiple runtimes.