Hypervisors used for virtualization
Type 1 Hypervisor – e.g. VMWare ESX, Citrix Xen Server, Linux KVM, Microsoft Hyper-V, MokaFive, XenClient – installed on bre-metal hardware as the OS – used for production server guests.
Type 2 Hypervisor – e.g VMWare Workstation (Windows), VMware Fusion & Player, Parallels (MAC), VMware Server, Microsoft Virtual PC, Virtual Box (Oracle), Linux KVM, Citrix Receiver – installed as an application inside an OS – used for development, demos, testing.