Try Firefox OS using the FF OS Simulator Browser Addon
There’s quite some buzz online about the Firefox OS. Here’s how you can get your hands on trying out the FF OS without having to go through too much of trouble.
There’s this “Firefox OS Simulator” addon available on FF Addons, which allows you to simulate FF OS from within your favourite browser (umm, Firefox)
The addon is naturally pretty heavy (67MB) as it has the OS contained within it. When installing the addon, it would take quite a while for FF to finish installing it. Also, the time taken could very well be more than the default timeout for FF’s script executioner, so you might see the “Unresponsive Script” dialog box. In such a case, click “Continue” and let FF install it completely. That should work.
The reviews of the addon are great too. Give it a try. FF OS Simulator Addon