KaOS is a lightweight, multi-purpose embedded Linux platform designed for virtualization and cloud computing applications. KaOS is based on Linux KVM and is a true enterprise grade hypervisor platform. KaOS makes it easy to deploy KVM based virtualization solutions. KaOS is a lightweight platform, less than 10MB in size. The SDK provides everything necessary to rebuild the platform and comes with scripts to assist with building a KaOS-enabled Linux kernel. KaOS has a menu-driven CLI called AppQueue and a management process that replaces init and other functions called kattach.
Proxmox is a Debian-based bundle of OpenVZ, KVM, and a Web based management GUI. It supports high-performance container-based virtualization of Linux workloads, as well as lower performance KVM hardware assisted virtualization. It supports any hardware that the Linux kernel supports, and will permit live migration of running OSIs with shared storage configurations (DRBD, CIFS, NFS, etc.). It comes bundled with many virtual appliance templates (Drupla, Moodle, FreePBX, etc.) and generic OSI appliances (Fedora, Debian, Ubuntu), as well as a faculty for building arbitrary Linux based appliances. It can be used for virtual desktop infrastructure (VDI) and virtual server infrastructure (VSI). It supports almost any x86/x64 OS in a KVM container and any Linux-based OS in OpenVZ.
Xvisor is a type-1 hypervisor that aims to provide a monolithic, light-weight, portable, and flexible virtualization solution for ARMv5, ARMv6, ARMv7a, ARMv7a-ve, ARMv8a, x86_64, and other CPU architectures. It primarily supports full virtualization, and hence supports a wide range of unmodified guest operating systems. Paravirtualization is optional and is supported in an architecture independent manner (such as VirtIO PCI/MMIO devices) to ensure that no changes are required in the guest OS.