There are times that I am amazed at the innovation coming from Open Source. One of these items I have found is in the Mandriva One Spring 2007.
For a little background, Mandriva (originally called Mandrake) was an offshoot of the Slackware distribution. Mandriva is actually a commercial distro, with a free version available, much like Linspire, Novell, and Red Hat. The system comes with either the GNOME or KDE desktop environments, with support for 32 and 64 bit systems.
What really surprised me was what came, by default, with the system. The first is Compiz, a 3-D desktop with transparency, which is what most Linux users are familiar with. However, the program that was the most amazing to me is called Metisse. Metisse has to be one of the most amazing window managers that I have ever seen. Not only is transparency supported, but windows can actually fold, onscreen. They can also flip, rotate on both ways. You can even flip the application around and look at it as if you are looking through the back of it.
Here is a link to the Mandriva Metisse site, where there are links to videos: