The project, available here, begins with the OS X boot screen and then brings you to the login screen. Once you enter the password (which is 'admin') you are taken to the desktop. The desktop features draggable windows, menu items and even buttons. Unless absolutely necessary (like user icons and backgrounds), Alessio has not used images at all. Everything you see in the project has been created via CSS3 properties.
Atzeni notes that this is only the first version and still missing several features that he will implement in the next release.
Check it out at the link below...
View More [via BeautifulPixels]