VMware vSphere Hypervisor is described as '( based on ESXi ) is a free bare-metal hypervisor that virtualizes servers so you can consolidate your applications on less hardware' and is a popular Virtualization tool in the network & admin category. There are more than 25 alternatives to VMware vSphere Hypervisor for a variety of platforms, including Linux, Self-Hosted, Windows, Mac and Web-based apps. The best VMware vSphere Hypervisor alternative is XCP-ng, which is both free and Open Source. Other great apps like VMware vSphere Hypervisor are Proxmox Virtual Environment, KVM (Kernel-based Virtual Machine), UTM and OpenStack.