Pale Moon (web browser)

Pale Moon 8 running on Windows XP (no longer supported)

Unbranded logo

Pale Moon has diverged from Firefox in a number of ways:

• Always runs in single-process mode, whereas Firefox became a multi-process program.[16][17]
• Replaces the Gecko browser engine with the Goanna fork
• Uses the pre-Australis Firefox user interface
• Continues add-on support for XUL, XPCOM, and NPAPI plugins, all of which are no longer supported in Firefox.[11]
• Supports add-ons exclusive to Pale Moon, including dozens of themes. These include retention of "Complete Themes", themes which apply to the entire UI of the browser rather than affecting only a few elements, support for which was removed in Firefox.[18]
• Defaults to a customizable start page in cooperation with start.me[19]
• Defaults to DuckDuckGo as the search engine instead of Google or Yahoo!
• Uses the IP-API service instead of Google's for geolocation[20]

M.C. Straver is the project founder and lead developer.[1] Straver's first official release of Pale Moon, in 2009, was a rebuild of Firefox 3.5.2 with tweaked compiler settings.[27] Eventually the scope of the project grew, and version 24 became a true fork of Firefox 24 ESR.[27] Starting with version 25, Pale Moon uses a completely independent versioning scheme.[28]

Pale Moon 27 was a major re-fork of the core browser code to Firefox 38 ESR, which added HTTP/2, DirectX 11, MSE/DASH, and JavaScript ES6 capabilities.[29] Add-on support remained almost entirely unchanged, with a slight reduction of Jetpack compatibility.[11][30]

In 2013, Pale Moon was a bit slower than Firefox in the ClubCompy Real-World Benchmark, with the browsers respectively scoring 8,168 and 9,344 points out of a possible 50,000.[42] In a 2016 browser comparison test by Ghacks, Pale Moon version 25 had the smallest memory footprint after opening 10 different websites in separate tabs.[43] However, in the same report Pale Moon scored bottom in the Mozilla Kraken, Google Octane, 32-bit RoboHornet tests and second-to-last in the 64-bit RoboHornet benchmarks. Whilst other browsers hung during some tests, Pale Moon only hung during the JetStream JavaScript benchmark.[43]

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.[44]

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."[45]

The questionable role of benchmarking was later confirmed by leading technology experts[46][47] when, for example, Google announced it was retiring its Octane benchmark in 2017,[48] 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".[49]

Worldwide market share according to StatCounter was stable at 0.02% between March 2019 and 2020.[50]

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.[51]

• Basilisk
• Waterfox

• Official website
• Pale Moon on Twitter