The SilveOS Project has released the first beta of SilveOS.com. SilveOS.com is an operating system (sometimes called a Web OS or a Webtop or a cloud computer) developed in Microsoft Silverlight

SilveOS.com is web-based and requires Silverlight 4 to operate. Application runs in Silverlight’s security sandbox. By default code is restricted from accessing your file system or doing anything that could hurt your machine. Besides desktop, taskbar, start menu and sidebar, currently it includes such applications:

File Explorer
Internet Explorer
Video Player
Rich test editor
RSS reader
Notepad
Paint
Twitter client
Flickr viewer
Youtube viewer
Virtual Earth
Chat
Calculator
Games like Chess, Solitaire, Spider, Minesweeper etc.
The system supports installing external software. But this program should be developed in Silverlight and be available in Internet or local file system.

SilveOS.com advantages:

Convenience and freedom - A personalized desktop, files, apps are available and accessible from any computer in the world.
No more administration - No more software installation, software update, worry about anti-virus.
Security - Less prone to typical attacks, viruses, worms, vulnerabilities, spyware and disk crashes.
Personalization – It includes such features as themes, wallpapers and user pictures management.
Hardware - Performance doesn't depend much on the speed of your computer.
Entertainment - Being online, SilveOS.com offers more opportunities for communicating and entertainment.
Cost - It is free.

  SilveOS.com Beta released