Forgetfulness?
I know it was mentioned here once, but I've read so many articles where people complain about VMWare and the rising costs, blah blah blah - we all know the story - and can't help but to also notice a trending forgetfulness around suggestions being made of other potential solutions, but almost everyone seemingly sleeping on KVM.
KVM and VMM (Virtual Machine Manager) make a potent and capable combination, and are entirely free. Kind of blows my mind that more people either don't appear to know about it or don't appear use it.