Cairo is an alternative Windows shell that will let you completely change your desktop from using the current Windows UI to a brand new system. The design team behind the project wants their shell to offer an elegant but functional alternative to the Windows desktop. The Cairo shell offers many different features, some of which can be found in standalone programs, but never all combined into one seamless shell replacement program. Some of the features include a Start-Bar to replace the Start menu, a dynamic desktop where you can browse files and folders right from the desktop, multiple desktops, a launcher, file/application grouping, and much more. The Cairo shell is currently in a private alpha, so stay tuned to their site to find out when it will be available to the public.