VMware developed/proprietary bare-metal hypervisor, which with vSphere 5 onwards is only available as ESXi (small foot-print without Console OS). The hypervisor itself is < 150MB. Device drivers are provided with the hypervisor (not with the Console OS or dom0/parent partition as with Xen or Hyper-V technologies).
ESX is based on binary translation (full virtualization) but also uses aspects of para-virtualization (device drivers, VMware tools and the VMI interface for para-virtualization) and supports hardware assisted virtualization aspects.