moby/hyperkit

HyperKit is a low-level toolkit for running virtual machines on a Mac. A virtual machine is a simulated computer that runs inside your real computer, completely isolated from the host system. HyperKit sits at the core of that process, handling the actual hardware virtualization. It is built on top of macOS's built-in Hypervisor.framework, which means it can create and run virtual machines without needing any kernel extensions or special drivers. It works on macOS 10.10 (Yosemite) or later, and only on Macs from 2010 onward whose CPUs support a feature called EPT. HyperKit is derived from xhyve, which itself came from bhyve, a hypervisor originally developed for FreeBSD. The project refines that lineage with a focus on lightweight virtual machines and containers. It is a core part of Docker Desktop for Mac, where it runs the small Linux virtual machine that Docker uses under the hood on macOS. Most Mac users who run Docker are indirectly using HyperKit without knowing it. As a standalone tool, HyperKit is meant to be embedded inside higher-level applications rather than used directly by end users. It is designed to work alongside companion projects such as VPNKit, which handles networking for virtual machines, and DataKit, which manages data access. Developers building tools that need to spin up virtual machines on a Mac can incorporate HyperKit as the underlying engine. Building it from source requires running make in the cloned repository. Optional support for a disk image format called qcow requires installing an OCaml development environment and several additional libraries. The README is brief and focused on technical setup.