Visopsys.org states - Visopsys is an alternative operating system for PC compatible computers. Under development since late 1997, this system is small, fast, and open source. It features a simple but attractive interface, real preemptive multitasking, and virtual memory. Though it attempts to be compatible in a number of ways, Visopsys is not a clone of any other operating system. You can demo the distribution from a "live" CD or floppy disk.

OSDir has some interesting screenshots of Visopsys 0.6 Preview.