Mozilla Labs has introduced its concept of a desktop replacement called Webian Shell. The Webian Shell basically consists of a browser which will replace the traditional desktop, and where the web applications are given more importance than the native applications. Right now, the prototype of the Webian Shell is nothing more than a full screen browser with a dock which holds the tabs and the clock.

The Webian Shell is developed using another Mozilla Labs project – Mozilla Chromeless. Mozilla Chromeless is a project which is looking to replace the traditional user interface of the browser with a more flexible platform based on HTML, CSS and JavaScript. The Webian Shell is just a shell that will run on top on an existing operating system – Windows, Linux or Mac OS X.
Webian Shell vs Chrome OS

It might not be wrong to say that Webian Shell could have been inspired by Google’s Chrome OS. However, the two are quite different right now.

Yes, there are similarities between the two in that both gives more priorities to the web by having a web browser for a desktop. But while Chrome OS is a complete operating system, Webian Shell is not. The Webian Shell runs on top of an existing operating system. Webian Shell cannot even control the hardware right now – it cannot control the system volume, network connections, show the battery indicator etc. Although hardware control is planned for a future release of Webian Shell, there is no plan of it becoming a full-blown operating system right now.

On tablets Windows 8 will support PlayBook like bezel gestures (the gestures actually take place on the first pixel next to the bezel, apparently not in the bezel itself). Gestures for the OS take place on the left/right edges of the screen, while app gestures happen on the top/bottom bezel.

Swipe in from the right to reveal the start button, and swipe in from the left to multitask. You just swipe between active apps like you would on a PlayBook.

The interface doesn’t require a touchscreen, Microsoft showed how you can multitask or switch between screens using a keyboard on a standard PC as well. This will be a common interface across all Windows 8 devices, tablet or standard PC.

Tapping the start button switches between the standard Windows desktop and the new tile interface. You can even display multiple applications on the screen at the same time using Windows 8′s snap feature.

With a widescreen display (apparently snap isn’t supported yet on 4:3s) you can display two apps side by side in the new tablet style UI:

You can even have a standard Windows 8 desktop on one side and a new Windows 8 app on the other. Microsoft also mentioned that Windows 8 will have the same system requirements or lower vs Windows 7.