For those wanting an alternative to VMWare or Parallels, <A target="_blank" href="http://www.virtualbox.org/">VirtualBox runs on</A> Windows, Linux, Macintosh and OpenSolaris hosts and supports a 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), Solaris and OpenSolaris, and OpenBSD.