Proxmox Virtual Environment, Limbo PC Emulator, Portable Virtualbox, KVM (Kernel-based Virtual Machine), Virtualizor, OpenStack, Bochs, UCS Virtual Machine Manager, Danube Cloud, XCP-ng, oVirt, Cloudmin, CoreCluster, bhyve, OpenNode Cloud Platform, xhypervisor, FAUMachine, SmartOS, VMware Server, Parallels Workstation, Karesansui, PetiteCloud are some alternatives to VMware vSphere Hypervisor.