QEMU

QEMU is a free, open-source machine emulator and virtualizer that can run full guest operating systems across many CPU architectures or execute foreign-architecture user-space binaries. It supports full-system emulation, hardware-assisted virtualization with KVM/Xen, and disk-image tooling such as qemu-img, making it useful for developers, infrastructure teams, and security testing workflows that need portable self-hosted virtualization.