I recommend Joyent (acquired by Samsung). They open source all their software (and make it easy to install and use). Their hypervisor operating system (SmartOS

I recommend Joyent (acquired by Samsung). They open source all their software (and make it easy to install and use). Their hypervisor operating system (SmartOS) rocks so hard. They also released Manta (S3 alternative object store). If Joyent ever changed direction, or shut down, I have an unlocked path forward with a community to help me continue on my own hardware. I can build my own cloud if push comes to shove.