📃 July 2025 release notes

Widely available

The following features are now widely available:

MathML: MathML, or the Mathematical Markup Language, describes mathematical notation, such as expressions and formulas. Also known as MathML Core.

The following features are now available in Firefox:

<dialog closedby>: The closedby HTML attribute for <dialog> sets which user actions close a dialog. For example, closedby="any" allows the dialog to be closed by clicking outside of it.
Explicit resource management: The using and await using declarations and the dispose and asyncDispose symbols manage the lifecycle of resources such as file handles and streams. The DisposableStack and AsyncDisposableStack objects can group, dispose, and coordinate dependencies between multiple disposable resources.
font-variant-emoji: The font-variant-emoji CSS property sets the default presentation for emoji characters.

The following features are now available in Firefox for Android:

<dialog closedby>: The closedby HTML attribute for <dialog> sets which user actions close a dialog. For example, closedby="any" allows the dialog to be closed by clicking outside of it.
Explicit resource management: The using and await using declarations and the dispose and asyncDispose symbols manage the lifecycle of resources such as file handles and streams. The DisposableStack and AsyncDisposableStack objects can group, dispose, and coordinate dependencies between multiple disposable resources.
font-variant-emoji: The font-variant-emoji CSS property sets the default presentation for emoji characters.