The screenshots below show several impressions while running VirtualBox on Linux, Windows and some soon-to-be-supported platforms:
VirtualBox for Mac OS X, currently in beta test. Two virtual machines are visible: one with Windows Vista, another with Gentoo Linux.
Creating a new, empty VM for installing Windows Vista.
The new VM in the VirtualBox main window. Note that an ISO file (containing the Vista setup CD) has been mounted as the VM's CD-ROM drive.
After starting the VM, it boots off the virtual CD-ROM (the ISO file with the Vista setup), and Vista Setup starts up.
Vista is installing into the virtual hard drive.
Vista install complete: the log-on screen.
Compiling VirtualBox on Ubuntu Edgy Eft in VirtualBox on Windows XP.
Details of a snapshot performed after Vista installation. We can revert the virtual machine to this snapshot at a later time.
Damn Small Linux 2.0 works damn well in VirtualBox!
The Virtual Disk Manager allows you to work with VM images.
VirtualBox in Vista inside VirtualBox on XP? Perhaps some day...
A community-based effort is underway to port VirtualBox to OS/2 hosts. This screenshot shows a first alpha version.