Proxmox VE is a free, open-source virtualisation platform that runs directly on a physical server, turning one machine into a host for full virtual machines and lightweight containers. But it is not the only bare-metal hypervisor: VMware ESXi, XCP-ng, and Hyper-V all solve the same problem differently, and the right choice depends far more on licensing, clustering, and your team's ecosystem than on raw features. This guide explains what Proxmox VE actually is, what a bare-metal hypervisor means, and how the four main contenders compare on cost, management, high availability, storage, and backup, with a side-by-side table, an opinionated decision framework, and links to the right server to deploy it on.