📃 December 2021 release notes

Newly available

The following features are newly available:

inputmode: The inputmode global HTML attribute gives a hint about what type of data is to be entered into an <input> element, such as text, numeric, or email, so the browser may help the user enter data using an adapted input mechanism, such as an on-screen virtual keyboard.
SharedArrayBuffer and Atomics: The SharedArrayBuffer object represents bytes shared between multiple workers and the main thread. The Atomics object safely accesses SharedArrayBuffer data to make sure predictable values are read and written and that operations are not interrupted.
Threads and atomics (WebAssembly): Threads in WebAssembly run code in parallel, while atomic memory instructions can guarantee that no two threads can read or write to shared memory at the same time.

The following features are now available in Firefox:

Page setup: The @page CSS at-rule sets the page-specific dimensions and margins for content such as printed documents, ebooks, or slides.

The following features are now available in Firefox for Android:

Cursor styles: The cursor CSS property styles the pointer, allowing you to provide hints to the user on how to interact with the hovered element.
Page setup: The @page CSS at-rule sets the page-specific dimensions and margins for content such as printed documents, ebooks, or slides.

The following features are now available in Safari:

Color management for 2D canvas: The optional colorSpace parameter of a 2D canvas's getContext() method chooses the color representation, such as "srgb" or "display-p3".
Exception handling (WebAssembly): Exceptions break the normal control flow of execution to represent exceptional behavior, such as an error. You can respond to the exception in JavaScript code.

The following features are now available in Safari on iOS:

Color management for 2D canvas: The optional colorSpace parameter of a 2D canvas's getContext() method chooses the color representation, such as "srgb" or "display-p3".
Exception handling (WebAssembly): Exceptions break the normal control flow of execution to represent exceptional behavior, such as an error. You can respond to the exception in JavaScript code.