Firefox 20 is now available for download. The emphasis of today’s release is on the new per-tab private browsing mode, which now allows Firefox desktop and Firefox for Android users to enable a single tab for private browsing instead of having to open a new window. Also new in this version is a new download manager for the desktop, the ability to customize the shortcuts on the home screen with your favorite sites and support for additional HTML5 and WebRTC features. The new version of Firefox for Android now also supports more devices that use less powerful ARMv6 processors, including the Samsung Galaxy Next, Dart, Pop and Q, as well as the HTC Aria and Legend. The new porn per-tab private browsing mode, Mozilla writes in today’s announcement, lets you “shop for a birthday gift in a private window with your existing browsing session uninterrupted.