I can't answer the question as to how dominant VMware is, in the entire market. I can say that ever single company I've worked for has used VMware for their vi

I can't answer the question as to how dominant VMware is, in the entire market. I can say that ever single company I've worked for has used VMware for their virtualization solution. I also use it for my business. It's pretty much ubiquitous, if you ask me. That said, I don't expect it to stay that way forever. <heavily opinionated part> Some folks say KVM performs better, but I haven't seen much difference in my experience. That, and KVM has little/no polish. Certain things are much more difficult to do with KVM, like create a VM with anything other than a NAT interface. There are LOTS of tools available for VMware. There just seem to be a lot of things that make VMware one of the easiest solutions to go with. I think ubiquity is part of that. If you're running something on VMware, and you want to relocate VMs, it's easy to do so. OpenStack - also messy, and not very easy to learn. I'd love to learn it, as I hear folks with OpenStack skills can make bank. It seems like a jumbled mess, though, and I have no idea where to start. </heavily opinionated part> :D