At its public launch in 2004 Mozilla Firefox was the very first internet browser to test Microsoft Internet Explorer’s supremacy. Download Firefox 57.0 Beta 7 Free 2018 Latest Download Firefox 57.0 Beta 7 Free 2018 Latest Version – Mozilla Firefox is a quick, light and also clean open resource web browser.It is based on the Goanna layout and rendering engine (a fork of Gecko) and builds on the Unified XUL Platform (UXP), which in turn is a fork of the Mozilla code base without Servo or Rust. Basilisk is a free and Open Source XUL-based web browser, featuring the well-known Firefox-style interface and operation.If Options isn't listed in the menu, select Customize and drag Options from the list of Additional Tools and Features over to the Menu. Or, on a Windows or Mac computer, enter about:preferences in a new tab or window. In Firefox for Mac, open the Firefox menu, then choose Preferences.