Virtualization is hot these days. It's amazing I can run multiple operating systems on one machine. I've tried some virtualization products, mostly open ones like QEMU and Bochs. They are generally slow, but good enough for playing. :)
However, virtualization doesn't merely mean that. Here I just found a good introduction article from osnews.com
http://www.kernelthread.com/publications/virtualization/, which seems a good starting point for exploring the technology.
