Mozilla developers are planning to build a dramatically different version of Firefox for Windows 8, a change necessitated by Microsoft’s use of the touch-friendly “Metro” user interface for PCs and tablets.

Mozilla describes its Windows 8 plans as part of a 2012 Strategy & Roadmap document updated yesterday. A technology proof-of-concept demonstrating the feasibility of Firefox in Windows 8 is planned for the second quarter of this year, with timing dependent on the release of Microsoft’s Windows 8 consumer preview and developer documentation. A Metro version may be necessary for Firefox to avoid being shut out of Windows 8 tablets running on ARM, which will have only a limited “traditional” Windows desktop. But Mozilla is apparently planning Firefox builds both for the traditional Windows desktop environment and Metro.

“Windows 8 contains two application environments, ‘Classic’ and ‘Metro,’” Mozilla notes. “Classic is very similar to the Windows 7 environment at this time, it requires a simple evolution of the current Firefox Windows product. Metro is an entirely new environment and requires a new Firefox front end and system integration points.”

Metro Firefox will be a new Gecko-based browser focused on touch interactions, with both full-screen and partial-screen modes, with the possibility of a live tile so that users can see updates on the Start screen. There are several unanswered questions, such as which programming language to use for building the Metro front end. Firefox product manager Asa Dotzler further notes that “This proposal depends on Microsoft providing the same capabilities for Firefox as it does for IE—running at the Medium level integrity process that allows us the full use of the Win32 API and what we need from Metro, or a set of APIs that allow Mozilla to port Gecko to the WinRT. For the purposes of this feature proposal, I’m assuming we’ll get the first and we won’t have to port the bulk of Gecko and instead will use the win32 dlls from within Metro.”

Firefox accounts for about 20 percent of worldwide desktop browser market share, but has lost ground to Google Chrome over the past year. Chrome will presumably have a Metro version for Windows 8 as well, but Google has made no official announcement.

This article originally appeared on Ars Technica, Wired’s sister site for in-depth technology news.

Mozilla is considering a fancier new tab page that will replace the current blank page presented when users create a new tab in Firefox. Like other browsers, Firefox will soon offer users a set of thumbnails on the new tab page with website recommendations based on the most frequently and recently visited pages in Firefox’s history.

If you’d like to see the new page in action you’ll need to download the Aurora channel build of Firefox. (Alternatively you can use the Nightly channel.) The new tab page will be enabled by default in Aurora until Feb. 16 for testing purposes. After that the feature will be hidden away while more work is done. Head over to Firefox Engineer Tim Taubert’s blog for details on how to re-enable the new tab page if you’d like to keep using it after that date.

The new tab page in Firefox looks similar to what you’ll find in Chrome and Opera. Indeed, every web browser’s new tab page is essentially a variation on what Opera pioneered with its “speed dial” page. The basic idea is to provide a quick way to access sites you frequently visit. Mozilla’s take thus far is to pull a mixture of your most frequently and most recently visited sites and display them in a 3-by-3 grid of thumbnails.

The goals for Firefox’s new tab page are ensuring that the page loads instantly, that it isn’t distracting and that it requires zero configuration. The latter explains why, thus far, the new tab features don’t offer much in the way of customization.

There are options to “pin” a site permanently to the grid, delete a site and rearrange the order of the sites. Each site will display a thumbnail once you’ve click on it. Or at least that’s the theory. As the screenshot above demonstrates there are clearly still some bugs in the screenshot feature.

The new tab page may be a little bit of a me-too feature at this point, but for those who have been wanting it, rest assured it’s coming. Firefox 13, which is when the fancier new tab page is slated to arrive is due in June 2012.

Mozilla has officially released Firefox 10. The new version of the open source web browser includes a handful of improvements and new features. The browser’s built-in tools for web developers got a particularly significant boost in this release. The new version also offers better support for a number of web standards.

Firefox’s developers decided last year to transition the browser to a time-based, six-week release cycle. The new release management strategy ensures that performance improvements and support for new web standards reach users as soon as possible. The faster release cycle posed challenges, however, for enterprise adopters and other users who require a longer support period. In order to address that issue, Mozilla has decided to offer an annual extended support release with a full year of updates. Firefox 10 is the first official extended support release.

A minor adjustment to the browser’s navigation bar is the biggest user-facing change in Firefox 10. The forward arrow button is no longer persistently visible by default in the navigation toolbar. It will only appear when the user navigates back a page. That means the button only shows when it can be activated. When the user clicks the forward arrow button and returns to the front of the history stack, the button will disappear again.

The distinctive keyhole shape that is formed by the back and forward buttons in Firefox’s navigation toolbar has been characterized in the past by Mozilla designers as an important part of the browser’s visual identity. Much like the angular tabs in Chrome, it’s an aesthetic characteristic that is uniform across platforms and helps make the browser recognizable.

The user interface change in Firefox 10 will make it so that the keyhole shape is only visible when the user navigates back. The feature worked predictably in our tests and didn’t pose any problems in practice. It’s worth noting, however, that it doesn’t appear to be available when the user has toggled the preference for small toolbar icons.

Another major change in Firefox 10 is the introduction of new developer tools. Previous versions of the browser have included a web console, a JavaScript scratchpad, and a simple tool for inspecting the Document Object Model (DOM). Firefox 10 has a new tightly-integrated developer panel with a richer DOM inspector and a tool for viewing, toggling, and modifying CSS properties.

The DOM inspector follows your cursor as you move it over elements of the page and will lock in on an element when you click. An HTML pane at the bottom of the screen will show you the markup for the target element and allow you to modify the values of element attributes. The HTML inspector pane also has a slick breadcrumb bar that makes it easy to see the position of the target element in the page hierarchy.

The CSS inspector will show you a list of CSS properties associated with the selected element, including inherited properties. Each one has a checkbox that you can click to toggle visibility. You can also click one of the values to replace it on the fly.

These built-in development tools in Firefox are simpler and less intrusive than more sophisticated alternatives such as the Firebug add-on. There are a number of additional features under development that will be included in the inspector panels in future versions of the web browser. One of the most intriguing is a tool that uses WebGL to show the user a three-dimensional representation of the page DOM. That feature wasn’t ready for inclusion in Firefox 10 and will potentially appear in the next major release.

In addition to the new inspector, web developers can also look forward to improved support for web standards. An addition of particular significance is a new full-screen API, which makes it possible for an individual HTML element to break out of the browser window and stretch itself to cover the entire screen. This feature is going to be especially useful for videos and games. You can see it in action by visiting Mozilla’s fullscreen demo page.

We first wrote about the full-screen API in November, when the feature originally landed in nightly builds. Mozilla carefully considered potential abuse scenarios when implementing the feature. It’s designed so that an element can only switch into fullscreen mode in response to a direct user action. The browser ensures this by using a technique similar to the one used to block unwanted popup windows.

Another addition in this release is support for 3D CSS transforms. This feature, which was originally created by Apple, offers a declarative mechanism for applying animated three dimensional transformations to individual HTML page elements. It’s important to note that 3D CSS transforms are entirely distinct from WebGL, which is a low-level JavaScript API for 3D programming.

Support for 3D CSS transformations is a welcome addition to the browser. Developers are already using the feature in the wild, but most of the existing 3D CSS content was authored with WebKit-specific prefixes and consequently won’t work in Firefox yet.

Firefox 10 is a solid release that expands the browser’s capabilities. Although the lineup of new features is slim, it’s a respectable update by the standards of the rapid release model. The new version will be pushed out through the Firefox update system shortly. Firefox 10 can also be downloaded directly from the Mozilla website. For more details, you can refer to the official release notes.

This article originally appeared on Ars Technica, Wired’s sister site for in-depth technology news.

Mozilla has released Firefox 9, which brings speed improvements and uses less memory than previous releases. In fact, this release effectively puts Firefox back on a level playing field with Google Chrome when it comes to speed.

If you’d like to try out Firefox 9, head on over to the Mozilla downloads page. If you’re already using Firefox you’ll be automatically updated to version 9.

The big news in this release is under the hood where Firefox now supports what’s known as Type Inference. Type Inference is a new feature for Firefox’s SpiderMonkey JavaScript engine and means that complex JavaScript websites — which, let’s face it, is pretty much every website these days — should run faster. According to Mozilla, Firefox 9′s Type Inference should make the browser between 20 and 30 percent faster.

Alongside the faster JavaScript processing Firefox 9 continues to show improvements from Mozilla’s MemShrink project, an ongoing effort to reduce memory usage in the browser. Indeed, for the first time in a very long time my testing showed Firefox 9 using less memory than Opera (which has long been the least RAM-hungry browser I test). Opening the same dozen tabs in both Firefox and Opera used only 367MB of RAM in Firefox compared to 378MB in Opera 11.60 [Update: Note that the memory test was performed with the following Firefox add-ons running: AdBlock, Ghostery, BetterPrivacy and HTTPS-Everywhere.] There’s no longer much difference between the two, which is a testament to Firefox’s dramatic improvement over the last six months of MemShrink efforts.

Web developers get a few new toys in this release, including a fullscreen mode that allows any HTML element to take over the screen. Although fullscreen is primarily associated with video elements, there may be occasions (for example, HTML elements used in web-based games) where it makes sense to take over the screen. For now the fullscreen feature needs the -moz prefix to work.

Firefox 9 also includes a new “dim the lights” feature for HTML5 video. Dimming the lights means that Firefox will overlay the rest of the browser window with a gray background that let’s you focus on the video in question. Check out this demo video which shows the dimming in action.

While most of what’s new in Firefox 9 is under the hood, Mac users will notice a few cosmetic changes like a slightly tweaked look and feel that more closely matches the Mac OS X Lion toolbar styles. There’s also now support for two-finger swipe gestures to navigate back and forth in history (mirroring the same features in Chrome and Safari).

Firefox 9 is well worth the upgrade. If you moved away from Firefox due to speed problems and bloat this release warrants another look. Those plagued by the rapid release cycle’s habit of breaking add-ons may want to hold off, though. Firefox 9, for all its other improvements, may still break some add-ons. Mozilla has a solution to the breaking add-ons problem in the works, but it won’t arrive for another six weeks when Firefox 10 is released.