In trying to re-use some old server hardware I re-vsisted VirtualBox/Ubuntu, a viable and completely free Open Source option for non-virtualization-enabled hardware. It is a neat solution, simple and well-supported, but the open source version of VirtualBox is nobbled to make it extremely awkward to use, in a different way to VMware’s nobbling of the non-Open Source (but also free) ESXi.
Now is the time, for Oracle/Sun to put all the features of VirtualBox into the Open Source version, and let it live on, perhaps not for use on Linux servers, but as free virtualization platform for other operating systems on Windows. If Apple ever loosens up the licencing on MacOS, it could turn 15 million PCs into Macs – overnight.