Mozilla Firefox

Mozilla Firefox is a free and open source web browser developed for Microsoft Windows, Mac OS X, and Linux coordinated by Mozilla Corporation and Mozilla Foundation. As of May 2012, Firefox has approximately 25% of worldwide usage share of web browsers, making it the third most widely used web browser. The browser has had particular success in Indonesia, Germany and Poland, where it is the most popular browser with 67%, 50% and 44% of the market share respectively. Firefox uses the Gecko layout engine to render web pages, which implements current and anticipated web standards.

History is Firefox 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 stand-alone browser, with which they intended to replace the Mozilla Suite. On April 3, 2003, the Mozilla Organization announced that they planned to change their focus from the Mozilla Suite to Firefox and Thunderbird.

Features is include tabbed browsing, spell checking, incremental find, live bookmarking, smart bookmarks, a download manager, private browsing, location-aware browsing (also known as "geolocation") based on a Google service and an integrated search system that uses Google by default in most localizations. Functions can be added through extensions, created by third-party developers, of which there is a wide selection, a feature that has attracted many of Firefox's users. 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, or extensions, such as Firebug.

Firefox implements many web standards, including HTML4 (partial HTML5), XML, XHTML, MathML, SVG 1.1 (partial), CSS (with extensions), ECMAScript (JavaScript), DOM, XSLT, XPath, and APNG (Animated PNG) images with alpha transparency. Firefox also implements standards proposals created by the WHATWG such as client-side storage, and canvas element. 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 a proprietary protocol from Google called "safebrowsing" (used to exchange data related with "phishing and malware protection").

Firefox uses a sandbox security model, and limits scripts from accessing data from other web sites based on the same origin policy. It uses SSL/TLS to protect communications with web servers using strong cryptography when using the HTTPS protocol. It also provides support for web applications to use smartcards for authentication purposes. The Mozilla Foundation offers a "bug bounty" (up to 3000 USD cash reward and a Mozilla T-shirt) 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 unpatched 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 reports that exploit code for known, critical unpatched 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 9 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. Symantec later clarified their statement, saying that Firefox still had fewer security vulnerabilities than Internet Explorer, as counted by security researchers. As of February 11, 2011, 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. In October 2009, Microsoft's security engineers acknowledged that Firefox was vulnerable since February of that year due to a .NET Framework 3.5 SP1 Windows update that silently installed a buggy 'Windows Presentation Foundation' plug-in into Firefox. This vulnerability has since been patched by Microsoft.

All patched vulnerabilities of Mozilla products are publicly listed.

When Firefox is upgraded to version 7.0, an information bar will appear asking users whether they would like to send performance statistics (also known as “telemetry”) to Mozilla. According to Mozilla's privacy policy, these statistics are stored only in aggregate format, and the only personally-identifiable information transmitted is the user's IP address.

Firefox is a heavily 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 and Chinese in Traditional Chinese characters/Simplified Chinese characters. Currently supported versions 10.0.4 and 12.0 are available for 85 locales (77 languages) and 86 locales (78 languages) respectively.