Hypervisors

A type 1 hypervisor provides virtualisation on a bare metal server. Type 2 runs within an OS. Type 1 hypervisors are more efficient and performant, but offer less flexibility. Also, type 1 hypervisors offer better security since OS vulnerabilies are limited to each virtual instance rather than the hypervisor OS, which could compromise all the hosted OSes at once.

Type 2 hypervisors, also known as hosted hypervisors or client hypervisors are easier to manage for some use cases, like software development

Type 1 hypervisors

• Xen
• Oracle VM (Xen based)
• Citrix Hypervisor (Xen based)
• KVM - a Kernel-based Virtual Machine, a hypervisor tech baked into the linux kernel, developed by Red Hat. It is used via c hooks, so a user would typically be making use of another piece of software that uses the KVM. For example, QEMU uses KVM as an accelerator.
• VMWare vSphere
• MS Hyper-V

Type 2 hypervisors

• Virtualbox is a type 2 hypervisor that runs on macos, windows or linux.
• Parallels Desktop
• VMWare Workstation & VMWare Fusion
• QEMU is an emulator and hypervisor, so you can run windows, mac and arm64 OSes on an x86 processor. It includes a range of processor recompilers jand hardware/peripheral emulators.
• Proxmox and libvirt (virsh, virt-manager) are both front-ends to QEMU.

Vagrant is an abstraction layer / way of managing VMs easily, independent of the underlying virtualisation software.