Mozilla has merged Firefox 9 on to the beta channel on November 10, 2011. The beta build is available for both desktop and Android users.Existing desktop Firefox 8 Beta users can update via Help > About Firefox or you can download Firefox 9 Beta from here. Android user should get an update notification or can get Firefox 9 Beta from the Android Market.

What’s New in Firefox Beta [More Info]:

• Type Inference: Firefox Beta adds Type Inference to make JavaScript significantly faster. To learn more about how rich websites and Web apps with lots of pictures, videos and 3D graphics will load faster in Firefox, check out this blog post.
• Mac OS X Lion Support: Firefox Beta has a new look that matches the Mac OS X Lion application toolbar and icon styles. Firefox Beta also supports the two finger swipe navigation gesture and makes it easier to use multiple monitors.
• Do Not Track JavaScript Detection: Firefox Beta enables JavaScript to show developers when users choose to opt-out of behavioral tracking with the Do Not Track privacy feature.
• Chunked XHR Support: Firefox Beta supports chunking for XHR requests so websites can receive data that’s part of a large XHR download in progress. This helps developers make websites and Web apps faster, especially those that download large sets of data or via AJAX.

What’s New in Firefox Beta for Android [More Info]:

• New Look for Tablets: Firefox Beta has a new experience for tablets that leverages the large screen size and makes mobile Web browsing more intuitive. Popular Firefox features like tabs and the Awesome Screen are optimized for tablets.
• Full-Screen Portrait Browsing: Firefox Beta takes advantage of large tablet screens so you can use the full screen to browse the Web, even in portrait mode. Tabs are listed in a top left menu and easily hide when you don’t need them.
• Tab Optimization: Tabs are shown as thumbnails in the left panel of Firefox Beta, allowing you to easily switch between tabs while still viewing full websites on the right. You can swipe to the left to hide tabs for a full screen view.
• New Action Bar with Quick Access Buttons: You can access Firefox Preferences, Add-ons, downloads and more in the new Action Bar menu (next to the Awesome Bar). The Action Bar adds back, forward and bookmark buttons for easy access.