#rrggbbaa hex color notation

The CSS Color Module Level 4 defines new 4 & 8 character hex notation for color to include the opacity level.

ECMAScript 2015 (ES6)

Support for the ECMAScript 2015 specification. Features include Promises, Modules, Classes, Template Literals, Arrow Functions, Let and Const, Default Parameters, Generators, Destructuring Assignment, Rest & Spread, Map/Set & WeakMap/WeakSet and many more.

JavaScript modules via script tag

Loading JavaScript module scripts (aka ES6 modules) using `<script type="module">` Includes support for the `nomodule` attribute.

JavaScript modules: dynamic import()

Loading JavaScript modules dynamically using the import() syntax

CSS Flexible Box Layout Module

Method of positioning elements in horizontal or vertical stacks. Support includes all properties prefixed with `flex`, as well as `display: flex`, `display: inline-flex`, `align-content`, `align-items`, `align-self`, `justify-content` and `order`.

CSS Font Loading

This CSS module defines a scripting interface to font faces in CSS, allowing font faces to be easily created and loaded from script. It also provides methods to track the loading status of an individual font, or of all the fonts on an entire page.

HTML Imports

Deprecated method of including and reusing HTML documents in other HTML documents. Superseded by ES modules.

Resource Hints: modulepreload

Using `<link rel="modulepreload">`, browsers can be informed to prefetch module scripts without having to execute them, allowing fine-grained control over when and how module resources are loaded.

gpudevice api: createshadermodule

serviceworker api: support for ecmascript modules

sharedworker api: `sharedworker()` constructor: support for ecmascript modules

worker api: `worker()` constructor: support for ecmascript modules

worklet api: support for ecmascript modules

css property: font-variant: css fonts module level 3 shorthand

ecmascript 2022 (es13)