- Firefox redirects here. For the novel and film of this title, see Firefox (novel and film). For other uses, see Firefox (disambiguation).
Mozilla Firefox is a free, open source web browser developed by the Mozilla Foundation. The software is licensed under the Mozilla Public License version 2.0 and is one of the main competitors of Microsoft's Internet Explorer, along with Google Chrome.. The current stable release is version 17.0.
Firefox was originally developed as an offshoot of the Mozilla Browser project, developed by Netscape, as a lightweight version of the software. The original Mozilla browser was extremely feature rich, including such things as an HTML editor, which created a large and correspondingly slow piece of software. Firefox has gone through several name changes, all due to existing trademarks. It was originally named Phoenix, then Firebird and finally Firefox.
Since its original release in 2002, Firefox has had a continued increase in the market share of web browsers until 2009, then a small decline due to competition from Google Chrome. Exact numbers are difficult to determine, but as of November 2012 worldwide, Firefox had a 24% share, and as of November 2012, 28.5% in Europe.
The browser is officially supported in over 70 languages, and is available for the different versions of Microsoft Windows, Apple Mac OS X, and Linux operating systems. Unofficial builds are available for Sun Microsystems Solaris, BSD, and other operating systems.