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 52.9.2026.06.12
UXP Changes: - Fixed a webaudio channel mixing regression resulting in broken audio. - 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. Note: AV1 is now enabled by default on non-x86 Basilisk builds. - 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). - 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...
Version history
| Version | Updated | Notes |
|---|---|---|
| 52.9.2026.06.12 | Unknown | UXP Changes: - Fixed a webaudio channel mixing regression resulting in broken audio. - Added powerPreference to canvas WebGL context for web compatibility. - Implemented support for the lch color space in CSS. - Added a... |
| 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... |