ECMAScript® 2024 Language Specification

Draft ECMA-262 / February 15, 2024

G Colophon

This specification is authored on GitHub in a plaintext source format called Ecmarkup. Ecmarkup is an HTML and Markdown dialect that provides a framework and toolset for authoring ECMAScript specifications in plaintext and processing the specification into a full-featured HTML rendering that follows the editorial conventions for this document. Ecmarkup builds on and integrates a number of other formats and technologies including Grammarkdown for defining syntax and Ecmarkdown for authoring algorithm steps. PDF renderings of this specification are produced by printing the HTML rendering to a PDF.

Prior editions of this specification were authored using Word—the Ecmarkup source text that formed the basis of this edition was produced by converting the ECMAScript 2015 Word document to Ecmarkup using an automated conversion tool.

About read262

read262 was originally created using Gatsby, but was ported to Eleventy in 2022. Some of read262’s CSS originated in the Gatsby blog starter I began the project with, while other CSS was copied over from the ecmarkup repository (see src/templates/ecmarkup.css), and the rest is my own.

The fonts used on read262 are Futura, Merriweather, and Fira Code. Search is provided by Algolia, and the site is hosted on GitHub Pages. Zapier is used to automate deploys whenever the spec repo is updated. The yellow color is copied from the JS logo.

read262 supports Dark Mode automatically.