Implemented support for single-use <link rel=preload> meta tag. This implementation allows use of it without specifying a second <link rel={type}> meta tag to actually load the linked document which was originally intended for this tag (to hint to a browser it should pre-load the document for fast painting).
Implemented CSP v3 keywords script-src-elem, script-src-attr, style-src-elem and style-src-attr.
Added support for Emoji 15.1.
Implemented webkitURL legacy window alias for URL for web compatibility.
Implemented CSS shorthands margin-block, margin-inline, padding-block and padding-inline.
Added support for querying CPU capabilities (SSE2/AVX/AVX2) to the Navigator interface. For privacy reasons this is not exposed to the web, but can be used by extensions.
Removed site-specific override for Amazon.com due to breakage.
Fixed an issue where empty MIME type registrations would break some parts of the UI.
(Linux only) Pasting URLs to content now by default does not navigate to that URL.
If content-paste-navigation is enabled (via middlemouse.contentLoadURL), navigation is now restricted to pasting to active body type elements (to prevent unwanted navigation when pasting URLs to input boxes, for example).
Fixed a problem with JS modules preventing ExportEntries from working.
(Linux only) Fixed a build issue when building with a system-supplied cairo library (unsupported).
Fixed an issue where workers could lock up the browser with SetInterval with an out-of-bounds (too small) value. This is now clamped to 4ms matching the HTML spec.
Fixed a few usability issues with the built-in developer tools.
Fixed a potential crash in web workers.
Fixed a potential overflow issue in image maps.
Fixed an issue with attributes on duplicate html tags.
Aligned the behavior of internal pointer structures to be more uniform. DiD
Fixed broken mousewheel scrolling if building with --disable-npapi.
Fixed a minor issue with XUL tree display in some circumstances.
Dev: Aligned canvas Path2D.addPath with the updated spec. It now supports DOMMatrix as opposed to SVGMatrix.
Removed Stylo (Gecko Rust style system) leftovers from the source tree.
Fixed a few potential emoji display issues. As usual, it is proven time and time again that emoticons are better

Fixed some issues with workers.
Fixed an issue with ctrl+c copying in devtools.
Fixed crashes when run under WINE because of its lack of support for IDXGIKeyedMutex.
Fixed a crash when dealing with a specific (unmaintained) extension.
Added .xrm-ms files to the executable warning list on Windows.
Added sanity checks on HTTP/2 header sizes.
Fixed a potential issue in the JavaScript JIT compiler.
Pulled a few fixes from upstream for the OpenType Sanitizer.
Added a fix to avoid a potential issue when assigning a media data buffer.
Security issues addressed: CVE-2024-1551, CVE-2024-2610, CVE-2024-3863, CVE-2024-3302, CVE-2024-3857 DiD, CVE-2024-3859 and CVE-2024-3861 DiD.