: ''[[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 [http://www.mozilla.org/foundation/ Mozilla Foundation]. The software is licensed under the ''Mozilla Public License version 1.1'' and is the main competitor of [[Microsoft]]'s [[Internet Explorer]]. The current stable release is version 3.6.
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. Exact numbers are difficult to determine, but as of April 2010, in North America Firefox had a 25% share<ref>[http://marketshare.hitslink.com/browser-market-share.aspx?qprid=0 Browser market share]</ref>, and as of March 2010, 30% in Europe<ref>[http://www.atinternet-institute.com/en-us/browsers-barometer/browser-barometer-march-2010/index-1-2-3-195.html AT Internet Institute - Article]</ref>.
The browser is officially supported in
53 languages<ref>[http://www.mozilla.com/en-US/firefox/all.html Firefox International Versions]</ref>, and is available for the different versions of Microsoft [[Windows]], [[Apple Inc.|Apple]] Mac [[OS X]], and [[Linux]] operating systems. Unofficial builds are available for Sun Microsystems Solaris, BSD and other operating systems.