Firefox 4 officially released by Mozilla

Mozilla has announced the official arrival of Firefox 4, the latest version of Europe's most popular browser, which it describes as "the fastest Firefox yet....between two and six times faster than previous releases".

Available in more than 80 languages, Firefox 4 is the result of over a year's worth of alpha and beta releases (17 in total), and the feedback of millions of testers. Since the first beta release back in July 2010, over 8,000 bugs and errors have been ironed out. 

It packs major improvements in terms of JavaScript performance, a swanky new look that makes more use of your display's real estate (File, Edit, View and the like are long gone) and there's a wide range of new features for you to take advantage of including App Tabs and the Panorama mode.

Security has also been ramped up. Nope, Mozilla hasn't got the Mitchell brothers to work the door - but it has added HTTP Strict Transport Security and the Content Security Policy.

Like Microsoft's recently launched IE9 browser, Firefox 4 is HTML 5 souped up and also offers anti-tracking tools. Unlike IE9, Firefox 4 will play nicely on Windows XP - as well as Mac OS X and Linux. Android and Maemo versions should be landing soon.

Let the browser wars commence.