In my day to day work, I need to have access to multiple operating systems in order to test various things. Unfortunatly running multiple desktops gets warm and traveling with multiple laptops gets cumbersome. I serached out and tried various virtualization technologies that would address my problems. In the end, after testing VMWare, various Xen ( Xen was purchased by Citrix ) incarnations, I finally settled on VirtualBox. Virtualbox was created and sold by Innotek. Sun eventually bought innotek in February of this year. VirtualBox allows you to install the software on a base system (called the “host”) and within the software you create multiple virtual computers with different operating systems (called “guests”).
This is similar to the way must virtualization applications work, and VirtualBox is pretty similar to VMWare. The one big difference with VirtualBox is that it’s free for personal use, and there is an open source edition as well. On my Dell laptop I am running Vista as the Host with Ubuntu Linux, Slackware Linux, Windows XP, Windows 2003 server, and FreeBSD as guests. In this configuration I allocate 1GB of ram for each guest operation system and can run 2 at the same time while reserving 1 GB for the host.
VirtualBox allows you to mount an ISO file for the guest CDROM drive, as well as pass through sound, networking, and USB devices. There is a guest add-on that has software you can install in most guests that will allow you to extend the abilities of the guest to the host. This allows for things like screen adjustments when you change the display size of the window or when going into full screen mode. One advantage that VirtualBox has it that it allows you to manage a guest remotly using RDP ( Windows Terminal Services protocol ) into the VM itself. This means I can start a FreeDOS guest and connect to the VirtualBox interface on a specific port for the guest rather then connecting to the guest itself.
VirtualBox is available for Windows, Linux, OS X, Solaris and OpenSolaris. Since VirtualBox is cross platform, I can install the virtual filesystem on an 16Gig HDSD card and open it on any computer with VirtualBox installed.