Mozilla Fennec beta offers performance, features
April 17, 2009 Software Review
Mozilla has announced the first official release of its mobile Firefox web browser, codenamed Fennec. The release 
includes significant performance improvements that speed up rendering and increase the responsiveness of the user interface.
Fennec’s user interface is designed to be finger-friendly and easy to use on touchscreen devices. It’s built with XUL, an XML-based user interface description language that is also used in the regular Firefox desktop browser. A sliding sidebar on the left-hand side displays a page switcher with thumbnail previews. The right-hand sidebar has basic navigation toolbar controls and a button that can activate the configuration panel. The user can access these sidebars by sharply dragging the page left or right.
Perhaps the most substantial improvement to content rendering performance in this Fennec release is the addition of TraceMonkey, Mozilla’s new high-performance JavaScript JIT engine which is built partially with technology contributed by Adobe from the Flash runtime. The ARM port of TraceMonkey doesn’t deliver the same kind of performance boost as the x86 version but it does quite well.
Fennec’s user interface shows that a lot of thought went into finding practical ways to save screen space. The URL bar, for example, typically shows the page title instead of the URL when it is not receiving text input. When the user types into the URL bar, it displays a scrollable pane of autocompletion results and search launchers in a more streamlined equivalent of Firefox’s AwesomeBar functionality.
Fennec extensions are built with XUL and JavaScript in much the same way that regular Firefox extensions are made. Some Fennec extensions have already been made or ported from the desktop version of Firefox, including popular ones like NoScript. These are available from a new Fennec section at the addons.mozilla.org website. There are a handful of nice Fennec-specific extensions, such as one that allows users to post messages to Twitter from the Fennec URL bar and one that adds basic gesture support. Mozilla has published documentation that explains how to build your own Fennec extensions.
Check out the official release notes and the release announcement by Mozilla’s Stuart Parmenter. Users can test the beta on an N810 with the one-click install or by running it on the desktop with the links provided in the release notes.
