ACRN Hypervisor vs Xen Project Hypervisor

ACRN Hypervisor is a free, open-source Type 1 hypervisor stack for embedded IoT development. It runs directly on Intel x86 bare-metal hardware and supports Linux, Windows and RTOS guests such as Zephyr; the project also lists VxWorks, Xenomai, Celadon and Android. CPU, I/O and networking virtualization are included, with I/O mediators for sharing graphics and audio across virtual machines. Resource partitioning is designed for safety-critical and non-safety-critical domains to coexist on one system-on-chip. The ACRN Device Model provides virtual device emulation. The project describes a codebase under 40K lines and reports low latency, fast boot times and responsive hardware communication. ACRN uses the BSD 3-Clause license, offers a command-line management interface and supports nested virtualization. Source code is maintained in a public GitHub repository with online documentation. Community help is available through mailing lists, IRC channels and monthly technical meetings.

Xen Project Hypervisor is a free, open-source type-1 hypervisor that runs multiple operating systems on one host. The project describes uses including server and desktop virtualization, IaaS, embedded systems, security applications, and hardware appliances. Linux is the most common control stack; NetBSD and FreeBSD are also named as host options. Xen’s microkernel design has a small memory footprint and restricts the interface exposed to guests. It can run a system’s main device driver inside a VM, allowing that VM to be restarted after a driver crash or compromise without affecting the rest of the system. On x86, fully paravirtualized guests can run without virtualization extensions. Listed capabilities include snapshots, nested virtualization, and GPU acceleration. The separate XAPI toolstack supports multi-host management, snapshots and migration, resource pools, storage migration, Open vSwitch, event tracking, upgrades, patching, and monitoring. Its built-in guest support and templates cover Windows and Linux. Downloads are source releases for building, packaging, and platform integration.