Mozilla's mobile Firefox could be available by year-end

The results of the open development process over the past 10 months have been impressive, says Kerry McGuire, director of strategic software alliances for ARM, the British chip maker with US offices in Austin, Texas. ARM licenses its CPU technology to such wireless giants as Qualcomm, Texas Instruments and others for a wide range of mobile devices. A couple of ARM engineers have been actively engaged in the mobile Firefox project, studying the issues of porting it to a range of the company's chip platforms, including several scheduled for release in early 2009.

McGuire says ARM noted two major innovations in the browser. One was quick work in slashing still further the amount of memory needed to run. "That's a tremendous contribution," she says.

Second was a dramatic improvement in how fast the JavaScript scripting language runs. "JavaScript is quite CPU-intensive," McGuire says. "We've seen a greater than five times performance improvement [in mobile Firefox]. Users will see this mainly in improved responsiveness."

Both changes were accomplished within months of the project's launch last fall, McGuire says. "Watching the code base change so quickly, so positively, that's a 'wow' moment for me," she says.

The all-important user interface

Like Safari, mobile Firefox will be able to work with a touchscreen but also will be available with a non-touch user interface. "We're spending a lot of time and resources on the user experience. This is really key," says Christian Sejersen, Mozilla's director of engineering.

Sejersen identifies several vital elements in optimizing that experience on a mobile device: devote as much of the screen's real estate as possible to the actual browsing experience, eliminating such things as onscreen buttons; make the interface very intuitive, so it's easy for the user to discover and use features; finally, make sure the interface doesn't hinder what you're trying to do.

As an example of his last point, Sejersen says Safari on the iPhone (which he calls a "great mobile browser") displays multiple browser windows as tabs. "If you zoom out to see multiple windows, you see a blank page: to reduce memory usage, it's thrown away," he says. "You [then] have to scroll between them to find which one you want. That takes a lot of time."

By contrast, a prototype of mobile Firefox lets the user drag the open Web page to one side, to reveal the additional pages that are open, a collection of thumbnail images: The user simply taps on the one he wants, and it fills the screen.

A recent "concept video" by Aza Raskin, head of user experience for Mozilla, demonstrated what he carefully calls a "possible direction" for the mobile browser's user interface.