Web developer Alessio Atzeni has accomplished an incredibly impressive feat of web design – recreating the entire Mac OS X Lion interface strictly through HTML5 and CSS3, complete with boot-up, login screen, and default desktop.
This impressive project, which you can see here, begins with the standard Mac OS X boot screen, progresses to the login screen (complete with password authentication), and finally to the desktop, which features draggable windows and menus, and even clickable buttons.
Even more impressive, Beautiful Pixels points out that none of the functional elements contain any graphics at all! The only graphics present in the entire project are the user icons and backgrounds. Everything else was created entirely using web languages.
Alessio explains the project in detail on his personal blog. Congrats, Alessio! Great work!