VMware vSphere Hypervisor is a free product

VMware vSphere Hypervisor":

VMware vSphere Hypervisor is a free product that provides a simple and easy way to get started with virtualization at no cost. vSphere Hypervisor provides only basic virtualization capabilities, allowing customers to virtualize servers and run applications in virtual machines in a matter of minutes.

vSphere Hypervisor cannot connect to vCenter Server and therefore cannot be centrally managed. Users can remotely manage individual vSphere Hypervisor hosts using the vSphere Client. vSphere Hypervisor can be utilized on servers with up to 32GB of physical RAM.

Source:

http://www.vmware.com/products/vsphere-hypervisor/overview.html

http://www.vmware.com/files/pdf/vsphere_pricing.pdf 

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