# Pale Moon 34.3.0_Release — Pale Moon 34.3.0

- Product: Pale Moon (https://whatsnew.fyi/product/pale-moon)
- Vendor: Moonchild Productions
- Date: 2026-06-02
- Version: 34.3.0_Release
- Original notes: https://repo.palemoon.org/MoonchildProductions/Pale-Moon/releases/tag/34.3.0_Release
- Permalink: https://whatsnew.fyi/product/pale-moon/releases/34.3.0-release
- Labels: Platforms: Windows, Linux

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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- **added** — Added powerPreference to canvas WebGL context for web compatibility
- **added** — Implemented support for the lch color space in CSS
- **added** — Added a base implementation for CSS stylesheet constructors
- **added** — Added a base implementation for CSS aspect-ratio sizing
- **added** — Added support for CSS min(), max() and clamp() functions
- **added** — Added support for CSS logical border radius properties
- **added** — Added support for ranges in CSS media queries
- **added** — Added support for CSS shadow parts
- **added** — Added support for degenerate CSS values infinity, -infinity and NaN
- **added** — Implemented full LoongArch64 Baseline/Ion/WASM JIT compiler support
- **added** — Added AV1 decoding with Dav1d for more performant AV1 video playback on 64-bit builds
- **added** — Added ES2024 Arraybuffer transfer APIs (resize, transfer, transferToFixedLength, detached, maxByteLength and resizable)
- **added** — Added support for growable/resizable SharedArrayBuffers and DataViews
- **added** — Added ES2024 grouping builtins (map .groupBy)
- **added** — Added ES2024 resolver builtins (.withResolvers())
- **added** — Added ES2024 String well-formed functions (.isWellFormed() and .toWellFormed())
- **added** — Added support for symbols as weak collection keys
- **added** — Added support for Atomics.waitAsync
- **added** — Added support for FinalizationRegistry (part of the WeakRef spec)
- **changed** — Switched build system to Python 3
- **changed** — Linux: Removed dbus-glib dependency
- **changed** — Linux: Added EGL as a preferred OpenGL provider with GLX fallback
- **changed** — Improved JS performance by porting various enhancements from Mozilla
- **changed** — Further improved compatibility with building for Loongson architectures
- **changed** — Further improved hardware accelerated decoding of WMF videos
- **changed** — Improved parallel JS parsing tasks
- **changed** — Improved CSS handling of calc() for web compatibility, allowing it in many more places
- **changed** — Aligned CSS border width calculations with mainstream for web compatibility
- **changed** — Changed the implementation of WeakRef support to be always enabled in its full implementation
- **fixed** — Fixed various application crashes
- **fixed** — Fixed ARM assembler issues in the Goanna back-end
- **fixed** — Fixed some build issues on NetBSD
- **fixed** — Fixed a pertinent crash due to font handling on OS X 10.7 through 10.11
- **fixed** — Fixed build compatibility with 32-bit MacOS and Mac on PowerPC hardware
- **fixed** — Fixed a devtools crash on Big Endian machines
- **fixed** — Fixed an issue causing rendering artifacts on excessively large border-radius values
- **removed** — Removed the CloudFlare workaround introduced in 34.2.0 as it should no longer be necessary with general image size handling improvements
- **security** — Fixed a stack corruption issue in nsLocaleService that could lead to crashes
- **security** — Implemented some ANGLE upstream fixes
- **security** — Updated NSS to 3.90.11 (UXP), picking up a number of upstream security fixes
- **security** — Performed a large security audit of 190 security-sensitive reported bugs, finding and fixing 18 potential vulnerabilities applicable to the codebase

This is a major development, bugfix and security release.
Special thanks to all the contributors (you know who you are!) for major work done on the platform internals this cycle, making Pale Moon better than ever :)

**New features:**

- Added powerPreference to canvas WebGL context for web compatibility.
- Implemented support for the `lch` color space in CSS.
- Added a base implementation for CSS stylesheet constructors.
- Added a base implementation for CSS `aspect-ratio` sizing.
- Added support for CSS `min()`, `max()` and `clamp()` functions.
- Added support for CSS logical border radius properties.
- Added support for ranges in CSS media queries.
- Added support for CSS shadow parts.
- Added support for degenerate CSS values `infinity`, `-infinity` and `NaN`.
- Implemented full LoongArch64 Baseline/Ion/WASM JIT compiler support.
- Added AV1 decoding with Dav1d for more performant AV1 video playback on 64-bit builds. See implementation notes.
      Note: AV1 is now enabled by default on Dav1d-supported configurations.
- Added ES2024 Arraybuffer transfer APIs (`resize`, `transfer`, `transferToFixedLength`, `detached`, `maxByteLength` and `resizable`).
- Added support for growable/resizable SharedArrayBuffers and DataViews.
- Added ES2024 grouping builtins (map `.groupBy`).
- Added ES2024 resolver builtins (`.withResolvers()`).
- Added ES2024 String well-formed functions (`.isWellFormed()` and `.toWellFormed()`).
- Added support for symbols as weak collection keys.
- Added support for `Atomics.waitAsync`.
- Added support for `FinalizationRegistry` (part of the `WeakRef` spec).

**Changes/fixes:**

- Switched our build system to Python 3. See implementation notes.
- Linux: removed `dbus-glib` dependency.
- Linux: Added EGL as a preferred OpenGL provider with GLX fallback; GLX remains the configured default as there are still some unresolved issues with EGL.
- Improved JS performance by porting across various enhancements from Mozilla.
- Fixed various application crashes.
- Further improved compatibility with building for Loongson architectures.
- Further improved hardware accelerated decoding of WMF videos.
- Fixed ARM assembler issues in the Goanna back-end.
- Improved parallel JS parsing tasks.
- Improved CSS handling of `calc()` for web compatibility, allowing it in many more places (e.g. `color()` and `z-index`).
      For compatibility and performance reasons, we still strongly recommend that you use CSS variables to make calculations where possible.
- Ported several smaller performance improvements from the Dactyloidae project.
- Aligned CSS border width calculations with mainstream, for web compatibility. Please note that this may impact some themes that might rely on fractional border rounding (instead of truncation).
- Removed the CloudFlare workaround introduced in 34.2.0 as it should no longer be necessary with general image size handling improvements. The preference will no longer do anything.
- White-listed driver vendors for VMWare, VirtualBox, VirtIO and Parallels to allow hardware accelleration as much as possible in VM environments.
- Changed the implementation of `WeakRef` support to be always enabled in its full implementation.
- Fixed some build issues on NetBSD.
- Mac: Fixed a pertinent crash due to font handling on OS X 10.7 through 10.11.
- Mac: Fixed build compatibility with 32-bit MacOS and Mac on PowerPC hardware.
- Fixed a devtools crash on Big Endian machines.
- Fixed an issue causing rendering artifacts on excessively large `border-radius` values (e.g. Tailwind CSS).

**Security fixes:**

- Fixed a stack corruption issue in nsLocaleService that could lead to crashes.
- Implemented some ANGLE upstream fixes.
- Updated NSS to 3.90.11 (UXP), picking up a number of upstream security fixes.
- Another large security audit was performed of 190 security-sensitive reported bugs. Many security issues were addressed, including potential crash scenarios a

_[Truncated at 4000 characters — full notes: https://repo.palemoon.org/MoonchildProductions/Pale-Moon/releases/tag/34.3.0_Release]_