Firefox 145.0

What's new in this version:

New:
- Copy Link to Highlight allows users to share arbitrary sections of page with others by copying a link through the context menu with a given selection
- Add, edit, and delete comments to make your own notes in PDFs (summaries, questions, tasks, etc.). The comment sidebar helps you scan all your comments and quickly jump to them, which is handy for long or heavily marked-up PDFs.
- Need a reminder of what tabs are in a group? Hover over the tab group name to get a preview of the tabs inside without opening it.
- Starting with Firefox 145, Nightly and Early-beta builds can now find previously visited pages using Semantic History Search, which lets users recall sites with natural-language and concept-based queries, all processed locally for privacy

Changed:
- Starting with Firefox 145, 32-bit Linux is no longer supported. We encourage users to install a 64-bit version of Firefox.
- Horizontal tabs are now slightly more round, following the look of vertical tabs. Buttons and text inputs, including the Address bar, have been updated as well for consistency.
- When a Firefox user has no extensions installed, and clicks the Extensions button on the toolbar, they will now see a message explaining how extensions can elevate their browsing experience with links to the Firefox add-ons store.

Developer:
CSS:
- The text-autospace property is now supported, allowing automatic spacing adjustments between characters from different scripts
- The math generic font family is now supported as a value of the font-family property, allowing mathematical expressions to use appropriate fonts

JavaScript:
- Firefox now supports the Atomics.waitAsync() static method, which allows synchronization of threads based upon the value in a shared memory location. The method waits asynchronously on the value and returns an object representing the result of the operation. It is non-blocking and usable on the main thread

HTTP:
- The Integrity-Policy and Integrity-Policy-Report-Only HTTP headers are now supported for script resources. These allow websites to enforce subresource integrity guarantees for scripts. Note that the endpoints key is not yet supported (violations are logged to console)

APIs:
- The source property of the ToggleEvent interface is now supported. If a popover is triggered to open or close by an HTML element such as a <button>, the event's source property will contain the element that triggered the popover
- A CSSStyleProperties instance is now returned for the style property on HTMLElement, MathMLElement, SVGElement, and CSSStyleRule, and the Window.getComputedStyle() method. Previously a CSSStyleDeclaration instance was returned

Media, WebRTC, and Web Audio:
- RTCEncodedVideoFrame and RTCEncodedAudioFrame are now serializable objects, and RTCEncodedAudioFrame() and RTCEncodedVideoFrame() copy constructors are supported. These changes allow frames to be cloned, and to be shared between workers and the main thread

Changes for add-on developers:
- Cookies created with cookies.set() are now validated, and invalid cookies are rejected. This change was implemented in Nightly only from Firefox 142

Experimental web features:
- These features are shipping in Firefox 145 but are disabled by default. To experiment with them, search for the appropriate preference on the about:config page and set it to true. You can find more such features on the Experimental features page.
- CSS anchor positioning (Nightly): layout.css.anchor-positioning.enabled:
- Nightly builds now support CSS anchor positioning by default, which allows you to tether elements together. The anchor-positioned elements can then have their size and position set relative to the size and location of the anchor elements to which they are bound. (General: Firefox bug 1988224, position-area: Firefox bug 1924086).

CSS module scripts: (Nightly) and layout.css.module-scripts.enabled:
- CSS module scripts are now supported, allowing a stylesheet to be loaded into a script as a CSSStyleSheet instance using the import keyword and the type import attribute set to type="css"
- text-decoration-trim: layout.css.text-decoration-trim.enabled
- The CSS text-decoration-trim property is supported but currently disabled by default. It allows you to specify text-decoration start and end offsets to shorten, lengthen, or shift the position of text decorations with respect to the text
- Trusted Types API for scripts (Nightly/Early Beta): dom.security.trusted_types.enabled
- The Trusted Types API is now enabled in early beta releases

The changes include:
- Addition of the TrustedTypePolicyFactory, TrustedTypePolicy, TrustedHTML, TrustedScript, TrustedScriptURL interfaces, and the trustedTypes property on Window and WorkerGlobalScope
- Updates to injection sink interfaces APIs, such as Element.innerHTML and document.write(), to allow the TrustedHTML, TrustedScript, TrustedScriptURL to be passed as well as strings
- Support for the require-trusted-types-for and trusted-types directives, and the 'trusted-types-eval' keyword, of the Content-Security-Policy HTTP header. These can be used to enforce trusted types instead of strings, name the specific policies that are allowed, and to enable eval() and similar functions to be used when Trusted Types are supported and enforced.

Web Platform:
- Support has been added for the Atomics.waitAsync proposal, which is a non-blocking, asynchronous version of Atomics.wait. This allow synchronization of threads based upon the value in a shared memory location, for more details please consult our MDN documentation.
- Firefox now partially supports the new Integrity-Policy header, which is used to enforce sub-resource integrity for scripts
- Added Matroska support for the most commonly used codecs: AVC, HEVC, VP8, VP9, AV1, AAC, Opus, and Vorbis
- The text-autospace property is now supported, allowing automatic spacing adjustments between characters from different scripts