Eventhough Leaked images of Firefox OS have released earlier,Now we have official Images from Mozilla.Our First Impression of Firefox OS is that its a mix of both Android and iOS.

It is still a work in progress but the OS looks visually attractive.The rounded icons seemed to be inspired from Nokia Belle while the Home Screen is clearly inspired from iOS.It has a drop-down notification bar as well, just like Android, along with system shortcut buttons we find in Samsung’s TouchWiz UI on its Android smartphones. Even the settings menu is similar to Android.
But the differentation will be in hardware as we expect Firefox OS to be less processor intensive than Android.
Firefox has released beta version of Firefox 13.It has some major changes.

When opening a new tab, users are now presented with their most visited pages
The default home page now has quicker access to bookmarks, history, settings, and more
SPDY protocol now enabled by default for faster browsing on supported sites
Restored background tabs are not loaded by default for faster startup
Smooth scrolling is now enabled by default
72 total improvements to Page Inspector, HTML panel, Style Inspector, Scratchpad and Style Editor
The column-fill CSS property has been implemented
Experimental support for ECMAScript 6 Map and Set objects has been implemented
Support for the CSS3 background-position property extended syntax has been added
The :invalid pseudo-class can now be applied to the element
The CSS turn unit is now supported
Firefox 14 has also been released for users on Aurora Build