QEMU

QEMU provides powerful hardware emulation, enabling you to run operating systems designed for different machine architectures (like ARM, RISC-V, or x86) on your own hardware. This free tool is invaluable for cross-platform development, firmware testing, and educational exploration. Beyond simple testing, it offers full system emulation for complete fidelity or user-mode emulation for running individual foreign programs. Its open-source nature means deep customization and integration into larger projects, making it a foundational tool for building secure, isolated testing environments before any real-world deployment.