download and run the browser on your Windows, Mac or Linux PC.
The new beta brings a slew of fixes and spit-shines, and for the first time it almost feels finished -- just in time, considering the final release is due in the next week or two. There are now over 100 mobile add-ons -- but, of course, in true Firefox beta fashion, fery few of them have been updated to work with the new beta. For a complete list of the changes and known issues, check the release notes.
Finally, you must check out the PC version of Firefox 4 for Mobile! It's an almost-perfect copy of the real deal: you can try out add-ons, and click-and-drag to simulate a touch interface. It's a lot easier to explore the (rather sexy) new UI with a proper desktop processor, and a keyboard and mouse, too.
Download Firefox 4 for Mobile beta 5 - Windows / Mac OS X / Linux
There's QR code for the Android build after the break.