The new Firefox 20, which is now available for download, includes some noteworthy usability and back-end changes, as well as updates the infamous "porn mode" that turns off the ability of the browser to record the browsing session of the users.

The key focus of the Firefox 20 is on the browser's private browsing mode which now enables the users of the Firefox desktop version to open a private browsing window without shutting down the whole browser. Users of Firefox for Android can, however, benefit from the use of per-tab private browsing; with the users now allowed to run private mode tabs beside the standard session tabs.

In addition, the new Firefox 20 version also features a Download Manager for the desktop. The new addition implies that the users no longer have to open a separate window for accessing downloads, as the new window appears in their toolbar next to the location bar. Moreover, the desktop's new Developer Toolbox especially facilitates the users who build Web sites by giving them the access to the requisite tools.

Firefox for Android, meanwhile, gives the users the advantage of customizing the shortcuts on the home screen with their favorite sites, so that they can get to the frequently-visited sites much faster.

Furthermore, on both the desktop and the Android versions of Firefox 20, the new browser brings along support for additional HTML5 and Web Real-Time Communication (WebRTC) features.