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.
BugOS is a microkernel operating system. It has a kernel, device drivers, a file system, and an Internet module. The main concepts are that every process has its own computer with its own console, security, and modularization. If a process wants to read the file, it asks the kernel. The kernel forwards the request to the filesystem driver, which reads and writes through the partition handler, which operates over the idehdd driver. The kernel is around 20 KB. Processes are fully separated from hardware.