So I love virtualization and emulation... I'm not a pro by any means, but I do find it cool that you can run multiple OSes together by virtualizing one or more inside another. Some great features of virtualization include the ability to test OSes before running them on real hardware, the ability to take screenshots (even when installing a virtual OS), the ability to use hard disk images that expand as you fill them up, etc... You can think of many more uses if you're creative... trust me. So, let's get down to business... Which virtualization software are you using/have you used? Is it good? What are the limitations and extra features? What is your host OS and what are your guess OSes? These days I typically use Sun VirtualBox because it's free and works great - haven't had a problem with it yet. I typically run my virtualization software inside Mac OS X (Snow Leopard) but there are times when I either run VirtualBox in Windows 7 or Windows XP or Microsoft Windows Virtual PC in Windows 7 to do XP Mode (which you can download for free from Microsoft's website). I've used Parallels Desktop and even VMWare Fusion in Mac OS X - they work fine as well, but I'm not really into paying for them. VirtualBox does it's job fine for the most part. As for guest OSes, I've run all sorts of Linux (Fedora Core 7, Ubuntu 9.04, DamnSmallLinux, openSUSE 11(?)), various Windows (Windows 1, Windows 3.1, Windows 3.11 for Workgroups, Windows NT 4, Windows 95, Windows 98(SE), Windows Me, Windows 2000, Windows XP, Windows Server 2008, Windows Vista, and even Windows 7), MS-DOS 6.2, FreeDOS, and last but not least, I've run Haiku (reincarnation of BeOS which I believe has its first alpha version released tomorrow after 8 years of development - check it out!). Anyone have any virtualizations on their computers?