Firefox

Mozilla Firefox (also known as Firefox Browser or simply Firefox) is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. It uses the Gecko rendering engine to display web pages. Firefox is available for Windows 7 or Windows 10, macOS, and Linux, with unofficial ports available for Unix and Unix-like operating systems including FreeBSD, OpenBSD, NetBSD, Illumos, and Solaris Unix. It is also available for Android and iOS. However, the iOS version uses the WebKit browser 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 Silk browser.

Firefox was created in 2002 under the codename "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 grew to a peak of 32.21% at the end of 2009, with Firefox 3.5 overtaking Internet Explorer 7, although not all versions of Internet Explorer as a whole. Usage then declined in competition with Google Chrome. As of May 2021, according to StatCounter, Firefox has 7.79% usage share as a "desktop" web browser, making it the fourth-most popular web browser after Google Chrome (67.53%), Safari (9.86%) and Microsoft Edge (7.96%), or arguably even with Edge, while its usage share across all platforms is lower at 3.59% still slightly ahead of Edge by same amount, enough for third place (after Google Chrome with 64.47% and Safari with 18.69%).

History
Firefox began as an experimental branch of the Mozilla project by David 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 this perceived 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. The nascent browsers 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 side-lined by Microsoft Internet Explorer in the "First Browser War"). Phoenix was renamed due to a trademark claim from Phoenix Technologies; the replacement name, Firebird, provoked an intense response from the Firebird database software project and was eventually changed to Mozilla Firefox on February 9, 2004. The name Firefox was said to be derived from the nickname of the red panda, which became the mascot for the newly named project.

Standards
Firefox supports HTML4 (almost complete HTML5), XML, MathML, SVG 2 (partial), CSS (with extensions), JavaScript, DOM, XSLT, XPath, and Animated PNG (APNG) images with alpha transparency.

Firefox supports standards proposals created by the WHATWG such as client-side storage and HTML5 canvas element, which are implemented through the Gecko layout engine and SpiderMonkey JavaScript engine.

Platform availability
The desktop version of of Firefox is available and supported for Microsoft Windows, MacOS, and Linux. Firefox for iOS is available for iOS 10.3 and later, and Firefox for Android is available for Android 4.1 and later.

Microsoft Windows
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, with Mozilla citing a lack of user adoption of the beta versions.