winget install --id Basilisk.BasiliskAbout Basilisk
Basilisk is a free and Open Source XUL-based web browser, featuring the well-known Firefox-style interface and operation. It is based on the Goanna layout and rendering engine (a fork of Gecko) and builds on the Unified XUL Platform (UXP), which in turn is a fork of the Mozilla code base without Servo or Rust.
What's new in 52.9.2026.04.15
UXP Changes: - Implemented ES2018 Proxy ownKeys duplicate-key invariant. - Implemented ES2022 Error.cause property. - Implemented support for oklab and oklch color spaces in CSS. - Implemented ES2024 object.GroupBy. - Implemented the remainder of the ES2023 Change Array by Copy proposal (toSpliced(), with(), and TypedArray versions of toReversed(), toSorted() and with()). - Implemented AudioNode constructors. - Implemented support for nested CSS grammar. - Implemented the window.MathMLElement global. - Fixed a crash related to WeakRef use. - Fixed stack exhaustion crashes as a result of top-level await in modules. - Updated our expat parser library to 2.7.4, fixing various issues. - Updated url.CanParse() to allow custom schemes. - Updated document.currentScript to align with the currently used spec. - Fixed a crash due to infinite recursion. - Fixed a crash on MacOS due to WebGL attribute arrays. - Fixed a crash related to pointer @media queries in CSS. - Fixed a crash related to the spellchecker when handling input fields in Shadow DOM. - Future-proofed whitespace handling in ParseDate in light of Unicode variable whitespace use. - Removed irrelevant plugin preferences when plugin support isn't built into the browser (non-standard builds/forks). - Improved support for the mimalloc memory allocator. - Improved support for LoongArch CPUs. - Added special handling for certain MacOS system fonts. - Removed leftover code for unsupported Itanium, 32-bit Sparc and other old architectures. - Added a workaround for CloudFlare image resizing, since it requires more opaque URL handl...
Version history
| Version | Updated | Notes |
|---|---|---|
| 52.9.2026.04.15 | Unknown | UXP Changes: - Implemented ES2018 Proxy ownKeys duplicate-key invariant. - Implemented ES2022 Error.cause property. - Implemented support for oklab and oklch color spaces in CSS. - Implemented ES2024 object.GroupBy. - Im... |
| 52.9.2026.03.09 | Unknown | UXP Changes: - Re-landed Xoroshiro128++ JavaScript PRNG to make it more robust while keeping high performance. This was previously backed out due to intermittent issues and crashes. - Implemented JavaScript SubmitEvent s... |
| 52.9.2026.01.23 | Unknown | UXP Changes: - Allow themes to detect Windows 11 usage. - Implemented WeakRef. - Implemented URL.canParse(). - Implemented the inset-block and inset-inline CSS shorthands. - Added a preference (privacy.forgetaboutsite.cl... |
| 52.9.2025.10.10 | Unknown | This Basilisk release integrates all Pale Moon changes from 33.8.1 through 33.9.1, introducing major web platform improvements, enhanced standards compliance, Linux stability fixes, and multiple security patches. - Imple... |
| 52.9.2025.07.04 | Unknown | This is a major development, bugfix and security release. - Basilisk now includes all non-ubiquitous image and media types in the navigation Accept: header, as discussed in the relevant whatwg fetch spec issue. - Impleme... |
| 52.9.2025.06.13 | Unknown | This is a bugfix and security release. - Fixed an issue where the Basilisk preferences would fail to open if the browser is compiled with --disable-webrtc. - Fixed a crash dealing with BigInt in Javascript compilation. -... |
| 52.9.2025.04.23 | Unknown | This is a development, bugfix, stability, and security release. - Implemented CSS two-location color stop logic. This allows for two-location color stops (`color x% y%`) in gradients, which is shorthand for `color x%, co... |
| 52.9.2025.02.22 | Unknown | This is a development, bugfix and security release. - Changed the way cookies are handled internally to fix an issue with cookie database corruption as a result of updates to domain suffixes. - Fixed an issue with Altern... |