Bochs
Bochs is a portable open source x86- and x86-64-architecture emulator mainly written in C++. It supports emulation of the processor(s) (including protected mode), memory, disks, display, ethernet, BIOS and common hardware peripherals of IBM PC compatibles.
Many guest operating systems can be run using the emulator including DOS, several versions of Windows, FreeBSD and Linux. Bochs can run on many host operating systems, including Windows, Linux, and OS X on the Mac.
Bochs is mostly used for operating system development (when an emulated operating system crashes, it does not crash the host operating system, so the emulated OS can be
