Mozilla Firefox (known simply as Firefox) is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. Firefox is available for Windows, OS X and Linux operating systems, with its mobile versions available for Android and Firefox OS. It uses the Gecko layout engine to render web pages, which implements current and anticipated web standards.
Firefox was created in 2002 under the name “Phoenix” by the Mozilla community members who wanted a standalone browser rather than the Mozilla Application Suite bundle. Even during its beta phase, Firefox proved to be popular by its testers and was praised for its speed, security and add-ons compared with Microsoft’s then-dominant Internet Explorer 6. Firefox was released in November 2004, and was highly successful with 60 million downloads within nine months, which was the first time that Internet Explorer’s dominance was challenged. Firefox is considered the spiritual successor of Netscape Navigator, as the Mozilla Foundation was created by Netscape in 1998 before their acquisition by AOL.
As of July 2015, Firefox has between 12% and 20% of worldwide usage as a “desktop” browser, making it, per different sources, the third most popular web browser.