Firefox
Mozilla Firefox is a free and open source web browser developed for Microsoft Windows, OS X, and Linux, coordinated by Mozilla Corporation and Mozilla Foundation. Firefox uses the Gecko layout engine to render web pages, which implements current and anticipated web standards.
As of October 2012, Firefox has approximately 20% to 24% of worldwide usage share of web browsers, making it the second or third most widely used web browser, according to different sources. According to Mozilla, Firefox counts with over 450 million users around the world. The browser has had particular success in Indonesia, Germany, and Poland, where it is the most popular browser with 65%, 47% and 47% of the market share, respectively.
Read more about Firefox: History, Features, Licensing, Promotion, Reception, Release History, Platform Support, System Requirements