The first beta build of mobile Firefox is now available to download for Android and Maemo-based handsets, Mozilla announced on Thursday.
The release is Mozilla's first browser to bring the Firefox brand name to mobile devices, as alpha builds of its WebKit mobile browser were codenamed Fennec.
Firefox 4 for mobile brings many of the same features as its desktop counterpart including the Awesome Bar, Firefox Sync options and support for add-ons. As well as incorporating desktop features, it has been optimised for touchscreen devices, allowing one-tap bookmarking, the ability to view tabs as thumbnails, and quick access to the Awesome Screen — a repository of favoured browsing history items and bookmarks.
The company says it has focused on fine-tuning its Electrolysis and Layers functions. Electrolysis was present in the Fennec release and provides process separation between the user interface (UI) and the rendering of web content. Layers is a new feature in Firefox 4 beta 1 mobile, and aims to speed up the responsiveness of scrolling, zooming and animations.
"Because of Electrolysis, we need to share layers between the UI process and the content process. These cross-process layers allow Firefox to scroll smoothly in response to user input, even if the content process is still busy rendering the page," wrote Matt Brubeck, a Mozilla Mobile engineer, in a blog post.
Mozilla notes on its blog that there is still a list of known bugs, including issues with Firefox's JIT compiler on Samsung Galaxy S phones.
"Even in this smaller set of devices, we've run into problems. Most recently, we discovered that Firefox's JIT code crashes unpredictably on Samsung Galaxy S phones. While we still don't know the exact cause, it seems likely to be a kernel bug," wrote Brubeck.
The beta is compatible with Android 2.0 and above and with Maemo devices such as the Nokia N900. It requires around 40MB of free space for installation. Currently, it only officially supports ARM v7-based Android handsets such as the HTC Desire, but there is an experimental beta available for earlier ARM v6 devices such as the HTC Hero.