The open systems revolution of the late 1980s and early 1990s, which espoused interoperability between platforms, made the various Unix operating systems the world’s most popular server platforms. If you consider Linux a kind of Unix, then you can argue that although Windows has spread into small and medium businesses, the Unix …
I see in here no consideration of non-Intel/AMD virtualization fabrics.
Opennebula left in the haze
I know which one there is really opensource.
The one that doesn't get all the marketing-budget funded raves.
Where's the evidence
Unix support and development costs cheaper? Not in my 'real world'...