This article relies too much on references to primary sources. (February 2018)
|Initial release||4 October 2009|
|29.2.1 (8 June 2021)|
|29.3.0a1 (rolling release)|
|Operating system||Windows 7 or later, Linux (contributed builds for various platforms)|
|Available in||37 languages|
Pale Moon is an open-source web browser with an emphasis on customizability; its motto is "Your browser, Your way". There are official releases for Microsoft Windows and Linux, as well as contributed builds for various platforms.
Pale Moon is a fork of Firefox with substantial divergence. The main differences are the user interface, add-on support, and running in single-process mode. Pale Moon retains the highly customizable user interface of the Firefox version 4–28 era. It also continues to support some types of add-ons and plugins that are no longer supported by Firefox, including NPAPI plugins such as Flash Player.
Pale Moon has diverged from Firefox in a number of ways:
Version 26.5 was the final official release to support Windows XP. Version 27.9.4 was the final official release to support Windows Vista as well as the final unofficial release for Mac OS X 10.6 Snow Leopard.
The end of XP support was quickly followed by Pale Moon getting at least two forks of its own, both of which take the most recent Pale Moon code and recompile it for XP; New Moon by roytam1, and Mypal by Feodor2.
The final version for Snow Leopard is the foundation for the Arctic Fox web browser.
Pale Moon's source code is released under the Mozilla Public License 2.0 except for parts relating to branding. To ensure quality, redistribution of officially branded Pale Moon binaries is only permissible under specific circumstances. The name and logo are trademarked by the project founder and cannot be used without his prior permission.
This section may be too technical for most readers to understand.(April 2020)
M.C. Straver is the project founder and lead developer. Straver's first official release of Pale Moon, in 2009, was a rebuild of Firefox 3.5.2 with tweaked compiler settings.[jargon] Eventually the scope of the project grew, and version 24 became a true fork of Firefox 24 ESR. Starting with version 25, Pale Moon uses a completely independent versioning scheme.
In 2017, the team behind Pale Moon began the Unified XUL Platform (UXP) project. UXP is an actively maintained fork with a historical fork point of the Mozilla code at Firefox 52 ESR with significant modifications to be a codebase for updated web technology support and creating any number of XUL-based applications.[jargon][clarification needed] To demonstrate, develop and refine the platform, Straver used it to create a new browser, Basilisk.
Pale Moon 28, released in August 2018, was the first version built on UXP, thereby providing improved support for web standards and video.
Pale Moon for Android was a distinct development effort that is no longer maintained. First released in 2014, Straver announced the following year that it would likely be abandoned due to lack of community involvement. The final release was 25.9.6.
On 10 March 2021 all Apple Macintosh support was dropped due to lack of consistency from community developers for the Mac platform.
|Version||Release date||Significant changes|
|3.5.2||9 October 2009||First public version.|
|3.6.x versions were Firefox rebuilds without code changes, and focused on optimizing the build parameters and build process.|
|4.0||Switched engine to be based on gecko/2.0.|
|5.0||Switched engine to be based on gecko/5.0.|
|6.0||Switched engine to be based on gecko/6.0.|
|7.0||Switched engine to be based on gecko/7.0.|
|8.0||Switched engine to be based on gecko/8.0.|
|9.0.1||Switched engine to be based on gecko/9.0.|
|9.1||Pale Moon is now built using MSVC (Microsoft Visual C Compiler) 10.0.|
|11.0||Switched engine to be based on gecko/11.0.|
|12.0||Switched engine to be based on gecko/12.0.|
|12.1||Major update, numerous security and stability fixes.|
|15.0||Switched engine to be based on gecko/15.0.|
|15.3||Pale Moon is now build using MSVC 11.0.|
|15.3.1||30 November 2012|
|15.3.2||5 December 2012|
|15.4||16 January 2013|
|15.4.1||28 January 2013|
|19.0||22 February 2013||Switched engine to be based on gecko/19.0.|
|19.0.1||24 February 2013|
|19.0.2||9 March 2013|
|20.0.1||11 April 2013||Switched engine to be based on gecko/20.0.|
|20.1||23 May 2013|
|20.2||1 July 2013|
|20.2.1||8 July 2013|
|20.3||13 August 2013|
|24.0||13 September 2013||Switched engine to be based on gecko/24-ESR (extended service release).|
|24.0.1||18 September 2013|
|24.0.2||27 September 2013|
|24.1.0||4 November 2013|
|24.1.1||5 November 2013|
|24.1.2||19 November 2013|
|24.2.0||26 November 2013|
|24.2.1||4 December 2013|
|24.2.2||11 December 2013|
|24.3.0||28 January 2014||Intel Atom optimized build introduced as a separate installation.|
Geo-location provider (used to find the geographical location of the browser user) switched from Google to IP-API.
|24.3.1||31 January 2014|
|24.3.2||11 February 2014||Support for TLS 1.2 introduced.|
First Pale Moon for Linux release.
|24.4.0||10 March 2014||Default search engine changed to DuckDuckGo.|
|24.4.1||19 March 2014|
|24.4.2||2 April 2014||Support for OCSP stapling introduced.|
|24.5.0||25 April 2014|
|24.6.0||6 June 2014||Rendering engine overhaul.|
From this version Pale Moon uses its own Sync server (to synchronize user data between different installations of the browser).
|24.6.1||8 June 2014|
|24.6.2||16 June 2014|
|24.7.0||29 July 2014|
|24.7.1||6 August 2014||First Pale Moon for Android (operating system) release.|
|24.7.2||11 September 2014||Last version to support Windows XP, with the exception of the Intel Atom optimized builds introduced with 24.3.0.|
|25.0.0||10 October 2014||Pale Moon now uses its own UUID (Universally unique identifier), allowing browser extensions to explicitly target Pale Moon.|
|25.0.1||15 October 2014|
|25.0.2||24 October 2014||SSL 3.0 is now disabled by default.|
|25.1.0||11 November 2014|
|25.1.1||28 November 2014||An Android-only update.|
|25.2.0||15 January 2015||Improved ES6 (ECMAScript version 6.0) draft implementation.|
|25.2.1||27 January 2015|
|25.3.0||13 March 2015|
|25.3.1||25 March 2015|
|25.3.2||25 April 2015|
|25.4.0||8 May 2015|
|25.4.1||10 May 2015|
|25.5.0||10 June 2015|
|25.6.0||15 July 2015|
|25.7.0||26 August 2015|
|25.7.1||28 September 2015|
|25.7.2||2 October 2015|
|25.7.3||14 October 2015|
|126.96.36.199||15 October 2015||An Android-only update.|
|25.8.0||17 November 2015|
|25.8.1||18 November 2015|
|26.0.0||26 January 2016||Layout engine is rebranded to Goanna.|
Basic support for ES6 Promises and WebP image format implemented.
A built-in XSS filter added.
|26.0.2||3 February 2016|
|26.0.3||5 February 2016|
|26.1.0||16 February 2016|
|26.1.1||24 February 2016|
|26.2.0||5 April 2016|
|26.2.1||8 April 2016|
|26.2.2||10 April 2016||An Android-only version 25.9.2 is released at the same time.|
|26.3.0||21 June 2016|
|26.3.1||25 June 2016|
|26.3.2||27 June 2016||A Microsoft Windows-only build.|
|26.3.3||1 July 2016|
|26.4.0||17 August 2016|
|188.8.131.52||23 August 2016||A Linux only build.|
|26.4.1||12 September 2016||Triple DES block cipher is now disabled by default for improved cryptographic security.|
|26.5.0||28 September 2016||This is the last version supporting Microsoft Windows XP.|
|27.0.0||22 November 2016||Pale Moon is now based on the Mozilla version 38 (Extended Service Release) platform code.|
Support for add-on SDK extensions dropped.
HTTP/2 implemented. Initial MSE (Media Source Extensions) implementation introduced.
|27.0.1||28 November 2016|
|27.0.2||2 December 2016|
|27.0.3||16 December 2016|
|27.1.0||9 February 2017||Media support code reworked; it now uses FFmpeg on Linux instead of GStreamer.|
|27.1.1||21 February 2017|
|27.1.2||3 March 2017|
|27.2.0||18 March 2017||Support for JPEG-XR implemented.|
|27.2.1||24 March 2017|
|27.3.0||28 April 2017||Media Source Extensions (MSE) implementation now adheres closer to the specification.|
|27.4.0||12 July 2017||Media Source Extensions (MSE) implementation now adheres fully to the established specification and can be used asynchronously.|
|27.4.1||3 August 2017|
|27.4.2||22 August 2017|
|184.108.40.206||28 August 2017|
|27.5.0||26 September 2017|
|27.5.1||10 October 2017|
|27.6.0||7 November 2017|
|27.6.1||15 November 2017|
|27.6.2||28 November 2017|
|27.7.0||15 January 2018|
|27.7.1||18 January 2018|
|27.7.2||2 February 2018|
|27.8.0||2 March 2018||Improved TLS 1.3 draft support.|
|27.8.1||6 March 2018|
|27.8.2||22 March 2018|
|27.8.3||28 March 2018|
|27.9.0||17 April 2018|
|27.9.1||7 May 2018|
|27.9.2||18 May 2018|
|27.9.3||12 June 2018|
|27.9.4||17 July 2018||This is the last version supporting Microsoft Windows Vista.|
|28.0.0||16 August 2018||Pale Moon is now based on the Unified XUL Platform (UXP).|
Nearly complete ES6 (ECMAScript version 6) support.
WebGL version 2, WebAssembly, CSS Grid and FLAC support introduced.
|220.127.116.11||28 August 2018|
|28.0.1||31 August 2018|
|28.1.0||20 September 2018||Final TLS 1.3 draft support implemented.|
|28.2.0||13 November 2018|
|28.2.1||16 November 2018|
|28.2.2||6 December 2018|
|28.3.0||15 January 2019||AV1 support introduced.|
|28.3.1||23 January 2019|
|28.4.0||19 February 2019|
|28.4.1||27 March 2019|
|28.5.0||30 April 2019|
|28.5.1||4 June 2019|
|28.5.2||5 June 2019|
|28.6.0||2 July 2019|
|18.104.22.168||4 July 2019|
|28.6.1||25 July 2019|
|28.7.0||29 August 2019|
|28.7.1||12 September 2019|
|28.7.2||29 October 2019|
|28.8.0||10 December 2019||Added support for modern Solaris (operating system).|
|28.8.1||11 January 2020|
|28.8.2||28 January 2020|
|22.214.171.124||4 February 2020|
|28.8.3||18 February 2020|
|28.8.4||1 March 2020|
|28.9.0||24 March 2020|
|126.96.36.199||25 March 2020|
|188.8.131.52||25 March 2020|
|28.9.1||10 April 2020|
|28.9.2||30 April 2020|
|28.9.3||8 May 2020|
|28.10.0||5 June 2020|
|28.11.0||15 July 2020|
|28.12.0||4 August 2020|
|28.13.0||4 September 2020|
|28.14.0||29 September 2020|
|28.14.1||30 September 2020|
|28.14.2||2 October 2020|
|28.15.0||27 October 2020|
|28.16.0||24 November 2020|
|28.17.0||18 December 2020|
|29.0.0||2 February 2021|
|29.0.1||6 February 2021|
|29.1.0||2 March 2021|
|29.1.1||30 March 2021|
|29.2.0||27 April 2021||Removed support for legacy Firefox extensions that are not updated for/targeting Pale Moon directly|
|29.2.1||8 June 2021|
Old, stable, testing
Current (UXP) versions of Pale Moon score comparatively to other browsers in benchmarks, showing, for example, no significant difference on the Sunspider benchmark compared to Firefox Quantum.
Straver has remarked that the role of benchmark tests is questionable, stating that they "can't be used to draw hard (or regularly even any) conclusions. Plain and simple: they are an indication, nothing more. They serve well if you compare closely related siblings (e.g. Firefox and Iceweasel) or different builds of the exact same browser, to get a relative performance difference between the two on the limited subset of what is actually tested, but that's about as far as it goes."
The questionable role of benchmarking was later confirmed by leading technology experts when, for example, Google announced it was retiring its Octane benchmark in 2017, and Mozilla indicating that they "believe these benchmarks are not representative of modern JS code" when introducing WarpBuilder in November 2020, admitting that their new technology "is currently slower than Ion on certain synthetic JS benchmarks such as Octane and Kraken".
This section needs expansion. You can help by adding to it. (May 2021)
Worldwide market share according to StatCounter was stable at 0.02% between March 2019 and 2020.
It was reported on 10 July 2019 that a data breach of the archive server holding previous binaries of the Pale Moon browser had occurred and malware inserted into the executables. This breach was discovered on the previous day. It is unknown when the breach first occurred. At first, it was estimated to have been as early as 27 December 2017, according to timestamps. After getting some more feedback from users, it is now estimated to have occurred somewhere between April and June 2019.
Pale Moon supports NPAPI plug-ins. Unlike Firefox, we will not be deprecating or removing support for these kinds of plug-ins. This means that you will be able to continue using your media, authentication, gaming, and other plug-ins in Pale Moon like Flash, Silverlight, bank-authenticators or networking plug-ins for specific purposes.
It was a bit disheartening to hear that v28.x SL builds will no longer be made but still…" "…Pale Moon 28 does not run on Snow Leopard.
Edited: 2021-06-18 12:38:58