Why settle for a basic build of your Firefox browser on Windows Operating Systems when you can have one that performs 25% faster? Mozilla does not provide optimized browser packages for Windows, while many Linux ("from scratch") users get the advantage of a browser built specifically for their system. That needs to change! So, here is the Pale Moon project: Custom-built and optimized Firefox browsers for Windows Operating Systems. Make sure to get the most speed out of your browser.

Of course, getting a faster browser is not just about optimizing the compilation process (building a program from its source code), but also about carefully choosing features and how to choose the best setup. This means that this browser, however extremely close to Firefox, does not have all the functions that Firefox has. A few, carefully selected, features have been disabled that are not in high demand, and that do not interfere with the way web pages are displayed or function; all to maximize speed and efficiency of the browser. Please see the page with technical details to learn exactly what the browser supports, and what it doesn't support. In short, if you need accessibility features or parental controls, then please visit the firefox homepage and get the official, non-optimized build.

Features:

  • Highly optimized for current processors
  • 100% Firefox sourced: As safe as the browser that has seen years of development.
  • Uses slightly less memory because of disabled redundant and optional code
  • Significant speed increases for page drawing and script processing
  • Support for SVG and Canvas
  • Support for Firefox extensions, themes and personas

What's New:

This is a development and security update to the browser.

Note for Linux users: With CentOS 6 going end-of-life, this version will be the last for which we will be building 32-bit Linux official binaries to download. While your distribution may choose to continue offering 32-bit versions of the browser, built from source by the maintainers, we won't be offering any further official 32-bit Linux binaries on our website. Please check with your distribution's package maintainers to know if further 32-bit support will be available on your particular flavor of Linux.
Changes/fixes:

  • Changed the way dates and times are formatted in the UI to properly adhere to the user's regional settings in the O.S.
  • Re-enabled the DOM Filesystem API for web compatibility.
  • Moved the global user-agent override to the networking component. See implementation notes.
  • Worked around crashes and run-time issues with module scripts. See implementation notes.
  • Fixed a website layout issue with table-styled elements potentially overlapping when placed inside a flexbox.
  • Fixed some code logic issues with websockets.
  • Fixed a regression when waking the computer from standby causing high CPU usage in some uncommon situations.
  • Updated the list of prohibited ports the browser can use. See implementation notes.
  • Updated root certificates.
  • Windows: Changed the way downloaded files without an extension are handled. See implementation notes.
  • Mac-beta: Improved version detection of MacOS including Big Sur.
  • Security issues addressed: CVE-2020-26978 and CVE-2020-35112.
  • Unified XUL Platform Mozilla Security Patch Summary: 2 fixed, 1 deferred to the next release, 16 not applicable.

Implementation notes:

  • The global user-agent override was moved to the networking component where it is actually implemented. The new preference name is network.http.useragent.global_override. Please note that using a blanket override is normally (very) counterproductive and does not, in fact, help much with privacy. It would also override the compatibility modes (Native/Gecko/Firefox) in Pale Moon. As such, the browser will now warn you if the user-agent is globally overridden (in preferences) and allow you to easily reset that override and re-enable the various compatibility modes.
  • Module scripting caused some persistent and very hard to track browser crashes that we've narrowed down to a specific optimization in the JavaScript JIT (Just-In-Time) compiler (IonMonkey). This optimization is now disabled by default but if you need that little extra performance (usually only noticed in very optimized code or some benchmarks) then you can re-enable it, trading in stability, by setting the new preference javascript.options.ion.inlining to true.
  • Prohibited ports: Pale Moon maintains a blacklist of ports the browser may normally not connect to on servers, to mitigate abusive web scripting employing your browser as an attack bot on servers (e.g. by connecting to mail servers or what not), NAT slipstreaming, and similar security issues. To more thoroughly prevent known abusable ports on servers, this list was extended with a number of additional default ports for various non-http protocols.
  • Downloaded files without a file extension: When a file without an extension is downloaded, we will now open the download folder where you may choose to take any specific action manually, instead of trying to execute it as a program or through an associated program.