What is ECMAScript?

In a nutshell

ECMAScript is a JavaScript standard that aims to make JavaScript implementations work the same across different environments. It’s standardized by Ecma International according to ECMA-262 (full document) and via the TC39 process. See this page for an overview of ECMAScript’s version history.

All JavaScript implementations such as V8, Chakra, and SpiderMonkey are built according to the ECMAScript standard. That’s why the same JavaScript code should (mostly) work the same in these different environments.

The ECMA-262 spec defines the syntax and semantics of the core ECMAScript API (e.g., Array, Function, and globalThis) with JavaScript implementations adding their own functionality (e.g., input/output or file system handling).

Other notes

• JavaScript was first released in 1995 by Brendan Eich of Netscape.
• You can view the source for the current draft of ECMA-262 on GitHub.

Sources / related

• ECMAScript version history
• ECMAScript – Wikipedia