
Sun's VirtualBox is a powerful virtualization software that allows you to run a number of operating systems from within your main, host operating system. You can install them, and pretty much abuse the 'guest OS', break it, tear it up from the inside out, and never hurt your main operating system. This is a great tool for people who want to learn about Operating Systems like Linux and BSD. Linux user's can even install it to run Windows inside their Linux environment if needed....