|Initial release||September 23, 2002|
|Engines||Gecko, Quantum, SpiderMonkey|
|Included with||Various Unix-like operating systems|
|Standard(s)||HTML5, CSS3, Atom|
|Available in||97 languages|
|Origins and lineage|
Mozilla Firefox or simply Firefox is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. Firefox uses the Gecko rendering engine to display web pages, which implements current and anticipated web standards. In 2017, Firefox began incorporating new technology under the code name Quantum to promote parallelism and a more intuitive user interface. Firefox is available for Windows 7 and later versions, macOS, and Linux. Its unofficial ports are available for various Unix and Unix-like operating systems, including FreeBSD, OpenBSD, NetBSD, illumos, and Solaris Unix. Firefox is also available for Android and iOS. However, the iOS version uses the WebKit layout engine instead of Gecko due to platform requirements, as with all other iOS web browsers. An optimized version of Firefox is also available on the Amazon Fire TV, as one of the two main browsers available with Amazon's Silk Browser.
Firefox was created in 2002 under the code name "Phoenix" by the Mozilla community members who desired a standalone browser, rather than the Mozilla Application Suite bundle. During its beta phase, Firefox proved to be popular with its testers and was praised for its speed, security, and add-ons compared to Microsoft's then-dominant Internet Explorer 6. Firefox was released on November 9, 2004, and challenged Internet Explorer's dominance with 60 million downloads within nine months. Firefox is the spiritual successor of Netscape Navigator, as the Mozilla community was created by Netscape in 1998 before their acquisition by AOL.
Firefox usage share grew to a peak of 32.21% in November 2009, with Firefox 3.5 overtaking Internet Explorer 7, although not all versions of Internet Explorer as a whole, its usage then declined in competition with Google Chrome. As of October 2021[update], according to StatCounter, Firefox has 7.87% usage share as a desktop web browser, making it the fourth-most popular desktop web browser after Google Chrome (67.17%), Safari (9.63%), and Microsoft Edge (9.14%), while its usage share across all platforms is lower at 3.66% in fourth place, after Google Chrome (64.67%), Safari (19.06%), and Edge (3.99%).
The project began as an experimental branch of the Mozilla project by Dave Hyatt, Joe Hewitt, and Blake Ross. They believed the commercial requirements of Netscape's sponsorship and developer-driven feature creep compromised the utility of the Mozilla browser. To combat what they saw as the Mozilla Suite's software bloat, they created a standalone browser, with which they intended to replace the Mozilla Suite. Version 0.1 was released on September 23, 2002. On April 3, 2003, the Mozilla Organization announced that they planned to change their focus from the Mozilla Suite to Firefox and Thunderbird.
The Firefox project has undergone several name changes. The nascent browser was originally named Phoenix, after the mythical bird that rose triumphantly from the ashes of its dead predecessor (in this case, from the "ashes" of Netscape Navigator, after it was sidelined by Microsoft Internet Explorer in the "First Browser War"). Phoenix was renamed in 2003 due to a trademark claim from Phoenix Technologies. The replacement name, Firebird, provoked an intense response from the Firebird database software project. The Mozilla Foundation reassured them that the browser would always bear the name Mozilla Firebird to avoid confusion. After further pressure, Mozilla Firebird became Mozilla Firefox on February 9, 2004. The name Firefox was said to be derived from a nickname of the red panda, which became the mascot for the newly named project. For the abbreviation of Firefox, Mozilla prefers Fx or fx, although it is often abbreviated as FF.
The Firefox project went through many versions before version 1.0 and had already gained a great deal of acclaim from numerous media outlets, such as Forbes and The Wall Street Journal. Among Firefox's popular features were the integrated pop-up blocker, tabbed browsing, and an extension mechanism for adding functionality. Although these features have already been available for some time in other browsers such as the Mozilla Suite and Opera, Firefox was the first of these browsers to have achieved large-scale adoption. Firefox attracted attention as an alternative to Internet Explorer, which had come under fire for its alleged poor program design and insecurity—detractors cite IE's lack of support for certain Web standards, use of the potentially dangerous ActiveX component, and vulnerability to spyware and malware installation. Microsoft responded by releasing Windows XP Service Pack 2, which added several important security features to Internet Explorer 6.
Version 1.0 of Firefox was released on November 9, 2004. This was followed by version 1.5 in November 2005, version 2.0 in October 2006, version 3.0 in June 2008, version 3.5 in June 2009, version 3.6 in January 2010, and version 4.0 in March 2011. From version 5 onwards, the development and release model changed into a "rapid" one; by the end of 2011 the stable release was version 9, and by the end of 2012 it reached version 17.
Major redesigns of its graphical user interface occurred on versions 4.0 in March 2011, 29.0 "Australis" in April 2014, 57.0 "Quantum" in November 2017, and 89.0 "Proton" in June 2021.
In 2016, Mozilla announced a project known as Quantum, which sought to improve Firefox's Gecko engine and other components to improve the browser's performance, modernize its architecture, and transition the browser to a multi-process model. These improvements came in the wake of decreasing market share to Google Chrome, as well as concerns that its performance was lapsing in comparison. Despite its improvements, these changes required existing add-ons for Firefox to be made incompatible with newer versions, in favor of a new extension system that is designed to be similar to Chrome and other recent browsers. Firefox 57, which was released in November 2017, was the first version to contain enhancements from Quantum, and has thus been named Firefox Quantum. A Mozilla executive stated that Quantum was the "biggest update" to the browser since version 1.0. Unresponsive and crashing pages only affect other pages loaded within the same process. While Chrome uses separate processes for each loaded tab, Firefox distributes tabs over four processes by default since Quantum in order to balance memory consumption and performance. The process count can be adjusted, where more processes increase performance at the cost of memory, therefore suitable for computers with larger RAM capacity.
On May 3, 2019, the expiration of an intermediate signing certificate on Mozilla servers caused Firefox to automatically disable and lock all browser extensions (add-ons). Mozilla began the roll-out of a fix shortly thereafter, using their Mozilla Studies component.
Main article: Features of Firefox
Features of the desktop edition include tabbed browsing, full-screen mode, spell checking, incremental search, smart bookmarks, bookmarking and downloading through drag and drop, a download manager, user profile management, private browsing, bookmark tags, bookmark exporting, offline mode, a screenshot tool, web development tools, a "page info" feature which shows a list of page metadata and multimedia items, a sophisticated configuration menu at
about:config for power users, and more location-aware browsing (also known as "geolocation") based on a Google service, and an integrated search system, which uses Google by default in most markets. Additionally, Firefox provides an environment for web developers in which they can use built-in tools, such as the Error Console or the DOM Inspector, and extensions, such as Firebug and more recently there has been an integration feature with Pocket. Firefox Hello was an implementation of WebRTC, added in October 2014, which allows users of Firefox and other compatible systems to have a video call, with the extra feature of screen and file sharing by sending a link to each other. Firefox Hello was scheduled to be removed in September 2016.
Former features include the ability to block images from individual domains (until version 72), a 3D page inspector (versions 11 to 46), tab grouping (until version 44), and the ability to add customized extra toolbars (until version 28).
Firefox can have themes added to it, which users can create or download from third parties to change the appearance of the browser. The Firefox add-on website also gives users the ability to add other applications such as games, ad-blockers, screenshot apps, and many other apps.
Firefox for Android was equipped with a guest session feature, introduced in 2013, which, when initiated, would memorize ordinary browsing data such as tabs, cookies, and history, but for the duration of the guest session. The guest session data would be kept even when restarting the browser or device, while deleted only upon a manual exit. The feature was removed, for which Mozilla claims to "streamline the experience".
Firefox has passed the Acid2 standards-compliance test since version 3.0. Mozilla had originally stated that they did not intend for Firefox to pass the Acid3 test fully because they believed that the SVG fonts part of the test had become outdated and irrelevant, due to WOFF being agreed upon as a standard by all major browser makers. Because the SVG font tests were removed from the Acid3 test in September 2011, Firefox 4 and greater scored 100/100.
Firefox also implements "Safe Browsing," a proprietary protocol from Google used to exchange data related with phishing and malware protection.
Since version 38 on Windows Vista and newer, Firefox supports the playback of video content protected by HTML5 Encrypted Media Extensions (EME). For security and privacy reasons, EME is implemented within a wrapper of open-source code that allows execution of a proprietary DRM module by Adobe Systems—Adobe Primetime Content Decryption Module (CDM). CDM runs within a "sandbox" environment to limit its access to the system and provide it a randomized device ID to prevent services from uniquely identifying the device for tracking purposes. The DRM module, once it has been downloaded, is enabled, and disabled in the same manner as other plug-ins. Since version 47, "Google's Widevine CDM on Windows and Mac OS X so streaming services like Amazon Video can switch from Silverlight to encrypted HTML5 video" is also supported. Mozilla justified its partnership with Adobe and Google by stating:
Firefox downloads and enables the Adobe Primetime and Google Widevine CDMs by default to give users a smooth experience on sites that require DRM. Each CDM runs in a separate container called a sandbox and you will be notified when a CDM is in use. You can also disable each CDM and opt-out of future updates— Watch DRM content on Firefox
and that it is "an important step on Mozilla's roadmap to remove NPAPI plugin support." Upon the introduction of EME support, builds of Firefox on Windows were also introduced that exclude support for EME. The Free Software Foundation and Cory Doctorow condemned Mozilla's decision to support EME.
See also: Browser security
The Mozilla Foundation offers a "bug bounty" (US$3,000 to US$7,500 cash reward) to researchers who discover severe security holes in Firefox. Official guidelines for handling security vulnerabilities discourage early disclosure of vulnerabilities so as not to give potential attackers an advantage in creating exploits.
Because Firefox generally has fewer publicly known security vulnerabilities than Internet Explorer (see Comparison of web browsers), improved security is often cited as a reason to switch from Internet Explorer to Firefox. The Washington Post reported that exploit code for known critical security vulnerabilities in Internet Explorer was available for 284 days in 2006. In comparison, exploit code for known, critical security vulnerabilities in Firefox was available for nine days before Mozilla issued a patch to remedy the problem.
A 2006 Symantec study showed that, although Firefox had surpassed other browsers in the number of vendor-confirmed vulnerabilities that year through September, these vulnerabilities were patched far more quickly than those found in other browsers, with Firefox's vulnerabilities being fixed on average one day after the exploit code was made available, as compared to nine days for Internet Explorer. Symantec later clarified their statement, saying that Firefox still had fewer security vulnerabilities than Internet Explorer, as counted by security researchers.
In October 2009, Microsoft's security engineers acknowledged that Firefox was vulnerable to a security issue found in the 'Windows Presentation Foundation' browser plug-in since February of that year. A .NET Framework 3.5 SP1 Windows Update had silently installed the vulnerable plug-in into Firefox. This vulnerability has since been patched by Microsoft.
In 2010, a study of the National Institute of Standards and Technology (NIST), based on data compiled from the National Vulnerability Database (NVD), Firefox was listed as the fifth-most vulnerable desktop software, with Internet Explorer as the eighth, and Google Chrome as the first.
InfoWorld has cited security experts saying that, as Firefox becomes more popular, more vulnerabilities will be found, a claim that Mitchell Baker, president of the Mozilla Foundation, has denied. "There is this idea that market share alone will make you have more vulnerabilities. It is not relational at all," she said.
As of February 11, 2011[update], Firefox 3.6 had no known unpatched security vulnerabilities according to Secunia. Internet Explorer 8 had five unpatched security vulnerabilities; the worst being rated "Less Critical" by Secunia. Mozilla claims that all patched vulnerabilities of Mozilla products are publicly listed.
Firefox 11, released in January 2012, introduced a 3D page inspector that visualizes web pages' document object model three-dimensionally through WebGL. The feature was accessible from the developer tools.
On January 28, 2013, Mozilla was recognized as the most trusted internet company for privacy in 2012. This study was performed by the Ponemon Institute and was a result of a survey from more than 100,000 consumers in the United States.
In February 2013, plans were announced for Firefox 22 to disable third-party cookies by default. However, the introduction of the feature was then delayed so Mozilla developers could "collect and analyze data on the effect of blocking some third-party cookies." Mozilla also collaborated with Stanford University's "Cookie Clearinghouse" project to develop a blacklist and whitelist of sites that will be used in the filter.
In January 2015, TorrentFreak reported that using Firefox when connected to the internet using a VPN can be a serious security issue due to the browser's support for WebRTC.
Beginning with Firefox 48, all extensions must be signed by Mozilla to be used in release and beta versions of Firefox. Firefox 43 blocked unsigned extensions but allowed enforcement of extension signing to be disabled. All extensions must be submitted to Mozilla Add-ons and be subject to code analysis in order to be signed, although extensions do not have to be listed on the service to be signed. On May 2, 2019, Mozilla announced that it would be strengthening the signature enforcement with methods that included the retroactive disabling of old extensions now deemed to be insecure. A Firefox update on May 3 led to bug reports about all extensions being disabled. This was found to be the result of an overlooked certificate and not the policy change set to go into effect on June 10.
In November 2018, Firefox began using a sandbox to isolate web tabs from each other and from the rest of the system. Its lack of such a feature had previously earned it negative comparisons with Google Chrome and Microsoft Edge.
Since version 60 Firefox includes the option to use DNS over HTTPS (DoH), which causes DNS lookup requests to be sent encrypted over the HTTPS protocol. To use this feature the user must set certain preferences beginning with "network.trr" (Trusted Recursive Resolver) in about:config: if network.trr.mode is 0, DoH is disabled; 1 activates DoH in addition to unencrypted DNS; 2 causes DoH to be used before unencrypted DNS; to use only DoH, the value must be 3. By setting network.trr.uri to the URL 188.8.131.52[permanent dead link], special Cloudflare servers will be activated. Mozilla has a privacy agreement with this server host that restricts their collection of information about incoming DNS requests.
On May 21, 2019, Firefox was updated to include the ability to block scripts that used a computer's CPU to mine cryptocurrency without a user's permission, in Firefox version 67.0. The update also allowed users to block known fingerprinting scripts that track their activity across the web, however it does not resist fingerprinting on its own.
On July 2, 2019, Mozilla introduced a mechanism to allow Firefox to automatically trust OS-installed certificates to prevent TLS errors.
In October 2019, ZDNet reported Firefox version 68 ESR passed all minimum requirements for mandatory security features during an exam by the Federal Office for Information Security of Germany.
In Mozilla Foundation Security Advisory 2020–03, the company reported that the CVE-2019-17026 vulnerability (type confusion vulnerability in IonMonkey) had been detected in the wild and was being actively exploited.
In March 2021, Firefox launched SmartBlock in version 87 to offer protection against cross-site tracking, without breaking the websites users visit.
Main article: Mozilla localizations
Firefox is a widely localized web browser. The first official release in November 2004 was available in 24 different languages and for 28 locales, including British English, American English, European Spanish, Argentine Spanish, Chinese in Traditional Chinese characters and Simplified Chinese characters and in Bengali script. As of November 2021[update], currently supported versions 94.0.2 and 91.2.0esr are available in 97 locales (88 languages).
The desktop version of Firefox is available and supports Microsoft Windows, macOS, and Linux, while Firefox for Android is available for Android (formerly Firefox for mobile, it also ran on Firefox OS).
|Operating system||Latest release||Support status|
|Windows||10 Fall Creators Update and later||Current stable version: 94.0.2  (ARM64)||2021-11-22||2015–|
|Older version, yet still maintained: 91.3.0 ESR  (ARM64)||2021-11-02|
|7 and later, Server 2008 R2 and later||Current stable version: 94.0.2  (x64)||2021-11-22||2009–|
|Older version, yet still maintained: 91.3.0 ESR  (x64)||2021-11-02|
|Current stable version: 94.0.2  (IA-32)||2021-11-22|
|Older version, yet still maintained: 91.3.0 ESR  (IA-32)||2021-11-02|
|XP SP2+, Vista,
Server 2003 SP1+ & R2 and Server 2008
|Old version, no longer maintained: 52.9.0esr (IA-32)||2018-06-26||2004–2018|
|Old version, no longer maintained: 52.0.2 (IA-32)||2017-03-28||2004–2017|
|2000, XP RTM & SP1 and
Server 2003 RTM
|Old version, no longer maintained: 10.0.12esr||2013-01-08||2004–2013|
|Old version, no longer maintained: 12.0||2012-04-24||2004–2012|
|NT 4.0 (IA-32), 98 and Me||Old version, no longer maintained: 184.108.40.206||2008-12-18||2004–2008|
|95||Old version, no longer maintained: 220.127.116.11||2007-05-30||2004–2007|
|macOS||10.12 (x64)/11 (ARM64) and later||Current stable version: 94.0.2 ||2021-11-22||2016– (x64)|
|Older version, yet still maintained: 91.3.0 ESR ||2021-11-02|
|10.9–10.11||Old version, no longer maintained: 78.15.0esr||2021-10-05||2013–2021|
|Old version, no longer maintained: 78.0.2||2020-07-09||2013–2020|
|10.6–10.8||Old version, no longer maintained: 45.9.0esr||2017-04-19||2009–2017|
|Old version, no longer maintained: 48.0.2||2016-08-24||2009–2016|
|10.5 (IA-32 and x64)||Old version, no longer maintained: 10.0.12esr||2013-01-08||2007–2013|
|Old version, no longer maintained: 16.0.2||2012-10-26||2007–2012|
|10.4 (IA-32 and PPC)–10.5 (PPC)||Old version, no longer maintained: 3.6.28||2012-03-13||2005–2012|
|10.2–10.3||Old version, no longer maintained: 18.104.22.168||2008-12-18||2004–2008|
|10.0–10.1||Old version, no longer maintained: 1.0.8||2006-04-13||2004–2006|
|GNU/Linux||Current stable version: 94.0.2  (x64)||2021-11-22||2011–|
|Older version, yet still maintained: 91.3.0 ESR  (x64)||2021-11-02|
|Current stable version: 94.0.2  (IA-32)||2021-11-22||2004–|
|Older version, yet still maintained: 91.3.0 ESR  (IA-32)||2021-11-02|
Firefox source code may be compiled for various operating systems; however, officially distributed binaries are provided for the following:
|Requirement||Microsoft Windows||Linux desktop||macOS||Android||iOS|
|CPU||Pentium 4 or newer with SSE2 (or ARM64 for Windows)||Any x86-64 and ARM64 CPU||ARMv7, ARM64, IA-32 and x64||ARM64|
|Memory (RAM)||512 MB for the 32-bit version and 2 GB for the 64-bit version||384 MB||?|
|Data storage device free space||200 MB||80 MB||?|
|Operating system||Windows 7 or later
Server 2008 R2 or later
||macOS 10.12 or newer||5.0 or newer||iOS 13 or later|
Firefox 1.0 was released for Windows 9x, as well as Windows NT 4.0 and later. Some users reported the 1.x builds were operable (but not installable) on Windows NT 3.51.
In September 2013, a Metro-style version of Firefox optimized for touchscreen use was introduced on the "Aurora" release channel. However, the project has since been canceled as of March 2014[update], with Mozilla citing a lack of user adoption of the beta versions.
Version 42.0 included the first x64 builds, made for Windows 7 and Server 2008 R2. Version 49.0 dropped support for processors without the SSE2 instruction set on Windows.
In April 2017, users of Firefox 52.0.2 on Windows XP, Windows Vista, Windows Server 2003 and Windows Server 2008 who had automatic updates enabled were migrated to Firefox 52 ESR. Support for these operating systems ended in June 2018.
The first official release (Firefox version 1.0) supported macOS (then called Mac OS X) on the PowerPC architecture. Mac OS X builds for the IA-32 architecture became available via a universal binary which debuted with Firefox 22.214.171.124 in 2006.
Starting with version 4.0, Firefox was released for the x64 architecture to which macOS had migrated. Version 4.0 also dropped support for PowerPC architecture, although other projects continued development of a PowerPC version of Firefox.
Firefox was originally released for Mac OS X 10.0 and higher. The minimum OS then increased to Mac OS X 10.2 in Firefox 1.5 and 10.4 in Firefox 3. Firefox 4 dropped support for Mac OS X 10.4 and PowerPC Macs, and Firefox 17 dropped support for Mac OS X 10.5 entirely. The system requirements were left unchanged until 2016, when Firefox 49 dropped support for Mac OS X 10.6–10.8. Most recently, Mozilla ended support for OS X 10.9–10.11 in Firefox 79, with those users being supported on the Firefox 78 ESR branch until November 2021.
Since its inception, Firefox for Linux supported the 32-bit memory architecture of the IA-32 instruction set. 64-bit builds were introduced in the 4.0 release. The 46.0 release replaced GTK 2.18 with 3.4 as a system requirement on Linux and other systems running X.Org. Starting with 53.0, the 32-bit builds require the SSE2 instruction set. Firefox also can run on number of other architectures on Linux, including ARM, AArch64, PowerPC, POWER, Sparc, HPPA, MIPS, s390, and in the past Alpha, IA-64 (Intel Itanium) and m68k.
Firefox for mobile is a web browser for mobile phones, tablets, and PDAs. It was originally first released for the Nokia Maemo operating system, specifically the Nokia N900, on January 28, 2010. On March 29, 2011, an Android version was released, being based on version 4. With the release of the mobile version, the browser's version number was bumped from 2 to 4, synchronizing it with all future desktop releases of Firefox because the rendering engines used in both browsers are the same. Version 7 was the last release for Maemo on the N900.
The former Firefox for Android (codenamed Fennec), was a web browser for Android devices, such as mobile phones and tablets. Its user interface was optimized for small screens and tablets. It included the Awesome Bar, tabbed browsing, add-on support, a password manager, location-aware browsing, and the ability to synchronize with the user's other devices with Mozilla Firefox using Firefox Sync. It was criticized for being slow, however, in part due to its poor port of Gecko. At the end of its existence, it had a marketshare of 0.5% on Android.
In August 2020, Mozilla launched a new version of its Firefox for Android app, named Firefox Daylight to the public and codenamed Fenix, after a little over a year of testing. It boasted higher speeds with its new GeckoView engine, which is described as being "the only independent web engine browser available on Android". It also added Enhanced Tracking Protection 2.0, a feature that blocks many known trackers on the Internet. It also added the ability to place the address bar on the bottom, and a new Collections feature. However, it was criticized for only having nine Add-ons at launch, and missing certain features. In response, Mozilla stated that they will allow more Add-ons with time.
|Operating system||Latest stable version||Support status|
|5.0 and later||Current stable version: 94.1.2 (x64)||2018–|
|Current stable version: 94.1.2 (ARM64)||2017–|
|Current stable version: 94.1.2 (IA-32 and ARMv7)||2014–|
|4.1–4.4||Old version, no longer maintained: 68.11.0 (x64)||2018–2020|
|Old version, no longer maintained: 68.11.0 (IA-32)||2013–2020|
|Old version, no longer maintained: 68.11.0 (ARMv7)||2012–2020|
|4.0||Old version, no longer maintained: 55.0.2 (IA-32)||2013–2017|
|Old version, no longer maintained: 55.0.2 (ARMv7)||2011–2017|
|3.0–3.2||Old version, no longer maintained: 45.0.2 (ARMv7)||2011–2016|
|2.3||Old version, no longer maintained: 47.0 (ARMv7)|
|2.2–4.3||Old version, no longer maintained: 31.3.0esr (ARMv6)||2012–2015|
|2.2||Old version, no longer maintained: 31.0 (ARMv7)||2011–2014|
|2.1||Old version, no longer maintained: 19.0.2 (ARMv6)||2012–2013|
|Old version, no longer maintained: 19.0.2 (ARMv7)||2011–2013|
|2.0||Old version, no longer maintained: 6.0.2 (ARMv7)||2011|
|Firefox OS||2.2||Old version, no longer maintained: 35/36/37||2015|
|2.1||Old version, no longer maintained: 33/34||2014–2015|
|2.0||Old version, no longer maintained: 31/32|
|Maemo||Old version, no longer maintained: 7.0.1||2010–2011|
Firefox Reality was released for Augmented Reality and Virtual Reality headsets in September 2018. It supports traditional web-browsing through 2D windows and immersive VR pages through Web VR. Firefox Reality is available on HTC Vive, Oculus, Google Daydream and Microsoft Hololens headsets.
Firefox has also been ported to FreeBSD, NetBSD, OpenBSD, OpenIndiana, OS/2, ArcaOS, SkyOS, RISC OS and BeOS/Haiku, and an unofficial rebranded version called Timberwolf has been available for AmigaOS 4. An unofficial continuation of the Mac OS X PowerPC release continues as TenFourFox.
The Firefox port for OpenBSD is maintained by Landry Breuil since 2010. Firefox is regularly built for the current branch of the operating system, the latest versions are packaged for each release and remain frozen until the next release. In 2017, Landry began hosting packages of newer Firefox versions for OpenBSD releases from 6.0 onwards, making them available to installations without the ports system.
The Solaris port of Firefox (including OpenSolaris) was maintained by the Oracle Solaris Desktop Beijing Team, until March 2017 when the team was disbanded. There was also an unofficial port of Firefox 3.6.x to IBM AIX and of v1.7.x to UnixWare.
|Operating system||Latest stable version||Support status|
|Solaris||11||Older version, yet still maintained: 91.3.0esr (x64,SPARC V9)||2011–|
|10 and OpenSolaris||Old version, no longer maintained: 52.9.0esr (IA-32,x64,SPARC V9)||2005–2018|
|8–9||Old version, no longer maintained: 126.96.36.199 (IA-32 and SPARC V9)||2004–2008|
|HP-UX||11i v2–v3||Old version, no longer maintained: 3.5.9 (IA-64,PA-RISC)||N/A|
|OpenBSD||-current||Current stable version: 94.0.2 (x64,ARM64)||2019–|
|Older version, yet still maintained: 91.3.0esr (x64,ARM64)|
|Old version, no longer maintained: 88.0.1 (IA-32)||2019–2021|
|Old version, no longer maintained: 78.14.0esr (IA-32)|
|-stable||7.0||Current stable version: 94.0.2 (x64,ARM64)||2021–|
|Older version, yet still maintained: 91.3.0esr (x64,ARM64)|
|6.9||Old version, no longer maintained: 88.0.1 (IA-32)||2021|
|Old version, no longer maintained: 78.14.0esr (IA-32)|
|5.8||Old version, no longer maintained: 38.7.1esr (PPC)||2015–2016|
|5.7||Old version, no longer maintained: 31.6.0esr (SPARC V9)||2015|
Besides official releases, Mozilla provides development builds of Firefox in distribution channels named, in order of most to least stable, "Beta", "Developer Edition" (formerly "Aurora", renamed on November 10, 2014), and "Nightly". Starting from Firefox 54, "Developer Edition" is based on the "Beta" build.
Firefox ESR (Extended Support Release) is a version of Firefox for organizations and other groups that need extended support for mass deployments. Each ESR release, based on the regular version released at the same time, is supported for one year. Unlike the regular ("rapid") releases, ESRs are not updated with new features and performance enhancements every four weeks, but rather are updated with only high-risk-reduction or high-impact security fixes or major stability fixes with point releases, until the end of the ESR cycle.
Firefox source code is free software, with most of it being released under the Mozilla Public License (MPL) version 2.0. This license permits anyone to view, modify, or redistribute the source code. As a result, several publicly released applications have been built from it, such as Netscape, Flock, Miro, GNU IceCat, Iceweasel, Songbird, Pale Moon, Waterfox, and Comodo IceDragon.
In the past, Firefox was licensed solely under the MPL, then version 1.1, which the Free Software Foundation criticized for being weak copyleft, as the license permitted, in limited ways, proprietary derivative works. Additionally, code only licensed under MPL 1.1 could not legally be linked with code under the GPL. To address these concerns, Mozilla re-licensed most of Firefox under the tri-license scheme of MPL 1.1, GPL 2.0, or LGPL 2.1. Since the re-licensing, developers were free to choose the license under which they received most of the code, to suit their intended use: GPL or LGPL linking and derivative works when one of those licenses is chosen, or MPL use (including the possibility of proprietary derivative works) if they chose the MPL. However, on January 3, 2012, Mozilla released the GPL-compatible MPL 2.0, and with the release of Firefox 13 on June 5, 2012, Mozilla used it to replace the tri-licensing scheme.
The crash reporting service was initially closed-source but switched with version 3 from a program called Talkback to the open-source Breakpad (and Socorro server).
See also: Mozilla software rebranded by Debian
The name "Mozilla Firefox" is a registered trademark; along with the official Firefox logo, it may only be used under certain terms and conditions. Anyone may redistribute the official binaries in unmodified form and use the Firefox name and branding for such distribution, but restrictions are placed on distributions which modify the underlying source code. The name "Firefox" derives from a nickname of the red panda.
Mozilla has placed the Firefox logo files under open-source licenses, but its trademark guidelines do not allow displaying altered or similar logos in contexts where trademark law applies.
There has been some controversy over the Mozilla Foundation's intentions in stopping certain open-source distributions from using the "Firefox" trademark. Open-source browsers "enable greater choice and innovation in the market rather than aiming for mass-market domination." Mozilla Foundation Chairperson Mitchell Baker explained in an interview in 2007 that distributions could freely use the Firefox trademark if they did not modify source code, and that the Mozilla Foundation's only concern was with users getting a consistent experience when they used "Firefox".
To allow distributions of the code without using the official branding, the Firefox build system contains a "branding switch". This switch, often used for alphas ("Auroras") of future Firefox versions, allows the code to be compiled without the official logo and name and can allow a derivative work unencumbered by restrictions on the Firefox trademark to be produced. In the unbranded build, the trademarked logo and name are replaced with a freely distributable generic globe logo and the name of the release series from which the modified version was derived.
Distributing modified versions of Firefox under the "Firefox" name required explicit approval from Mozilla for the changes made to the underlying code, and required the use of all of the official branding. For example, it was not permissible to use the name "Firefox" without also using the official logo. When the Debian project decided to stop using the official Firefox logo in 2006 (because Mozilla's copyright restrictions at the time were incompatible with Debian's guidelines), they were told by a representative of the Mozilla Foundation that this was not acceptable and was asked either to comply with the published trademark guidelines or cease using the "Firefox" name in their distribution. Debian switched to branding their modified version of Firefox "Iceweasel" (but in 2016 switched back to Firefox), along with other Mozilla software. GNU IceCat is another derived version of Firefox distributed by the GNU Project, which maintains its separate branding.
The Firefox icon is a trademark used to designate the official Mozilla build of the Firefox software and builds of official distribution partners. For this reason, software distributors who distribute modified versions of Firefox do not use the icon.
Early Firebird and Phoenix releases of Firefox were considered to have reasonable visual designs but fell short when compared to many other professional software packages. In October 2003, professional interface designer Steven Garrity authored an article covering everything he considered to be wrong with Mozilla's visual identity.
Shortly afterwards, the Mozilla Foundation invited Garrity to head up the new visual identity team. The release of Firefox 0.8 in February 2004 saw the introduction of the new branding efforts. Included were new icon designs by silverorange, a group of web developers with a long-standing relationship with Mozilla. The final renderings are by Jon Hicks, who had worked on Camino. The logo was later revised and updated, fixing several flaws found when it was enlarged. The animal shown in the logo is a stylized fox, although "firefox" is usually a common name for the red panda. The panda, according to Hicks, "didn't really conjure up the right imagery" and was not widely known.
In June 2019, Mozilla unveiled a revised Firefox logo, which was officially implemented on version 70. The new logo is part of an effort to build a brand system around Firefox and its complementary apps and services, which are now being promoted as a suite under the Firefox brand.
Firefox was adopted rapidly, with 100 million downloads in its first year of availability. This was followed by a series of aggressive marketing campaigns starting in 2004 with a series of events Blake Ross and Asa Dotzler called "marketing weeks".
Firefox continued to heavily market itself by releasing a marketing portal dubbed "Spread Firefox" (SFX) on September 12, 2004, It debuted along with the Firefox Preview Release, creating a centralized space for the discussion of various marketing techniques. The release of their manifesto stated that "the Mozilla project is a global community of people who believe that openness, innovation and opportunity are key to the continued health of the Internet." A two-page ad in the edition of December 16 of The New York Times, placed by Mozilla Foundation in coordination with Spread Firefox, featured the names of the thousands of people worldwide who contributed to the Mozilla Foundation's fundraising campaign to support the launch of the Firefox 1.0 web browser. SFX portal enhanced the "Get Firefox" button program, giving users "referrer points" as an incentive. The site lists the top 250 referrers. From time to time, the SFX team or SFX members launch marketing events organized at the Spread Firefox website. As a part of the Spread Firefox campaign, there was an attempt to break the world download record with the release of Firefox 3. This resulted in an official certified Guinness world record, with over eight million downloads. In February 2011, Mozilla announced that it would be retiring Spread Firefox (SFX). Three months later, in May 2011, Mozilla officially closed Spread Firefox. Mozilla wrote that "there are currently plans to create a new iteration of this website [Spread Firefox] at a later date."
In celebration of the third anniversary of the founding of the Mozilla Foundation, the "World Firefox Day" campaign was established on July 15, 2006, and ran until September 15, 2006. Participants registered themselves and a friend on the website for nomination to have their names displayed on the Firefox Friends Wall, a digital wall that was displayed at the headquarters of the Mozilla Foundation.
The Firefox community has also engaged in the promotion of their web browser. In 2006, some of Firefox's contributors from Oregon State University made a crop circle of the Firefox logo in an oat field near Amity, Oregon, near the intersection of Lafayette Highway and Walnut Hill Road. After Firefox reached 500 million downloads on February 21, 2008, the Firefox community celebrated by visiting Freerice to earn 500 million grains of rice.
Other initiatives included Live Chat – a service Mozilla launched in 2007 that allowed users to seek technical support from volunteers. The service was later retired.
To promote the launch of Firefox Quantum in November 2017, Mozilla partnered with Reggie Watts to produce a series of TV ads and social media content.
In December 2005, Internet Week ran an article in which many readers reported high memory usage in Firefox 1.5. Mozilla developers said that the higher memory use of Firefox 1.5 was at least partially due to the new fast backwards-and-forwards (FastBack) feature. Other known causes of memory problems were malfunctioning extensions such as Google Toolbar and some older versions of AdBlock, or plug-ins, such as older versions of Adobe Acrobat Reader. When PC Magazine in 2006 compared memory usage of Firefox 2, Opera 9, and Internet Explorer 7, they found that Firefox used approximately as much memory as each of the other two browsers.
In 2006, Softpedia noted that Firefox 1.5 took longer to start up than other browsers, which was confirmed by further speed tests.
Internet Explorer 6 launched more swiftly than Firefox 1.5 on Windows XP since many of its components were built into the OS and loaded during system startup. As a workaround for the issue, a preloader application was created that loaded components of Firefox on startup, similar to Internet Explorer. A Windows Vista feature called SuperFetch performs a similar task of preloading Firefox if it is used often enough.
Tests performed by PC World and Zimbra in 2006 indicated that Firefox 2 used less memory than Internet Explorer 7. Firefox 3 used less memory than Internet Explorer 7, Opera 9.50 Beta, Safari 3.1 Beta, and Firefox 2 in tests performed by Mozilla, CyberNet, and The Browser World. In mid-2009, BetaNews benchmarked Firefox 3.5 and declared that it performed "nearly ten times better on XP than Microsoft Internet Explorer 7".
In January 2014, a benchmark testing the memory usage of Firefox 29, Google Chrome 34, and Internet Explorer 11 indicated that Firefox used the least memory when a substantial number of tabs were open.
Support for blocking images from individual domains has been removed from Firefox, because of low usage and poor user experience.
From Firefox 47 onwards, 3D view is no longer available.
Do not use this protocol without explicit written permission from Google. Note: This is not a license to use the defined protocol. [...]
I suggest dumping Microsoft's Internet Explorer Web browser, which has a history of security breaches. I recommend instead Mozilla Firefox, which is free at mozilla.org. It's not only more secure but also more modern and advanced, with tabbed browsing, which allows multiple pages to be open on one screen, and a better pop-up ad blocker than the belated one Microsoft recently added to IE.
This is the English Translation of Previous Citation.
Version 35.0a2, first offered to Firefox Developer Edition users in November 2014