CDHaha Download

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.

Basilisk as an application is primarily a vessel for development of the XUL platform it builds upon, and additionally a potential replacement for Firefox to retain the use of Firefox Extensions.

Basilisk is development software. This means that it should be considered more or less “beta” at all times; it may have some bugs and is provided as-is, with potential defects. Like any other Free Software community project, it comes without any warranty or promise of fitness for any particular purpose. That being said: of course we will do our best to provide an as stable and secure browser as possible with every official release of Basilisk.

It should be noted that because of this focus on platform development, the browser itself (the application code) will be released and maintained mostly as-it-is, with very little change or development on the user interface or browser front-end features.

Basilisk is a modern, full-featured web browser and as such requires a reasonably modern system to properly run.
Windows requirements

Windows 7 or later. Windows XP or Windows Vista are not supported.
1GB of RAM (2GB or more recommended for heavy use).
Dedicated GPU strongly recommended.
A modern processor (must have SSE2 support as the absolute minimum)

Important differences with Mozilla Firefox:

Uses Goanna as a layout and rendering engine. Goanna behaves slightly differently than Gecko in certain respects and may result in different display of web pages. e.g.: Goanna renders gradients in a more accurate color space (non-premultiplied).
Builds on UXP, our XUL platform in development. As such XUL is alive and well in this browser and will not be deprecated.
Has some long-standing known issues with the Mozilla code-base fixed (e.g. CVE-2009-1232).
Does not use Rust or the Photon user interface. You can expect a familiar interface as-carried by Firefox between v29 and v56.
Does not use Electrolysis (e10s, multi-process browsing).
Does not require walled-garden extension signing.

These release notes are summaries of the most important changes for public releases.

v2026.03.09
Published 2026-03-09
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 support for HTML forms.
Implemented JavaScript requestSubmit() for HTML forms.
Implemented JavaScript toSorted().
Implemented JavaScript toReversed().
Implemented top-level await support for JavaScript modules. See implementation notes.
Implemented pointer and hover CSS media queries.
Enabled hardware-accelerated decoding for VP9 videos (where possible).
Re-landed our expat library update, with fixes for large attribute parsing.
Updated the JPEG-XL library to 0.11.2 to pick up security and performance fixes, and applied a spot-fix for big-endian hardware.
Updated libtheora to 1.2.0.
Updated libvpx to 1.16.0 with various fixes to retain compatibility with older MacOS and PowerPC platforms.
Basilisk, from this version forward, allows unencrypted websocket connections to localhost addresses even when the calling document was served encrypted.
Fixed an issue in the new Cascade Layers implementation causing problems with UI elements and extensions.
Fixed several issues with the new ICU library implementation in UXP:
Fixed an issue where it was returning unexpected Unicode spaces in date strings instead of standard space characters, causing problems with web scripting.
Fixed an issue with plural forms for Shuar, Welsh and several Slavic languages.
Fixed an issue with letter dots in Lithuanian.
Fixed an issue with word-wrapping in Tibetan.
Fixed an intermittent browser crash related to removing cached image data, and improved image data cache handling as a whole.
Further improved compatibility with Mac on PowerPC hardware.
Restored support for building on 32-bit MacOS 10.6.
Applied miscellaneous fixes for building on MacOS 10.5 (Leopard) and 10.6 (Snow Leopard).
Fixed run-time issues on FreeBSD 15.*.
Fixed an issue with applying image filters on big-endian hardware.
Fixed an issue preventing bundled fonts from working properly on targets other than Windows or Linux-GTK.
Fixed crashes on long browsing sessions on sites making heavy use of WeakRef.
Built on UXP commit: a268e57967
Security issues addressed: CVE-2026-2806 (DiD), CVE-2026-2758, CVE-2026-2804, CVE-2026-2787 (DiD), CVE-2026-2757, CVE-2026-2773, CVE-2026-2779 (DiD), CVE-2026-2775, and several others that do not have a CVE designation.

Basilisk Changes:
LoongArch64 builds are now built on Loongnix Server 23.
Introduced Mac OS X 10.5 PowerPC builds.
We no longer differentiate between beta/alpha/etc. for builds. All builds are welcome here <3 Included Polyfills: This release includes the following polyfills: image.decode Intl.DisplayNames Intl.Segmenter en-US only Intl.ListFormat Microsoft-specific (Outlook, Azure, etc) webauthn shim TextEncoderStream ReadableStream pipeTo ReadableStream pipeThrough FinalizationRegistry Basilisk Update Notes: Added logging to the console when polyfills are loaded. Improved spec compliance in ReadableStream polyfill. Enabled getAnimations by default. UXP Implementation Notes: Top-level await for JavaScript modules has been implemented. This allows the use of the await keyword at the top level without a wrapper to force pseudo-synchronous processing in async modules. This completes the last landmark issue of our ES2022 compatibility. Most notably, the lack of this would result in websites using certain frameworks to render completely blank. [Downlink href="http://jp.basilisk-browser.org/release/basilisk-latest.win64.installer.exe"]64bit[/Downlink] [Downlink href="http://jp.basilisk-browser.org/release/basilisk-latest.win64.zip"]64bit Zip[/Downlink]