I’ve long been a fan of using virtualization to run Linux under Windows or Windows under Linux. I’ve even used virtualization to host Windows under Windows or Linux under Linux so I can change things around with impunity or test something with an “old” operating system. I’ve used VirtualPC, VMWare, and Parallels. InnoTek recently made their virtualization product open source. From their Web site:

Presently, VirtualBox runs on Windows and Linux 32-bit hosts and supports a large number of guest operating systems including but not limited to Windows (NT 4.0, 2000, XP, Server 2003, Vista), DOS/Windows 3.x, Linux (2.4 and 2.6), and OpenBSD.

Here’s the link:

VirtualBox