Bochs (box) is a portable IA-32 and x86-64 IBM PC compatible emulator and debugger mostly written in C++ and distributed as free software under the GNU Lesser General Public License. Developed by http://bochs.sourceforge.net/
License: Open Source
Bochs is primarily aimed at educational purposes and legacy hardware emulation, making it slower and less user-friendly. In contrast, QEMU offers better performance, a wider range of supported operating systems, and is suitable for modern virtualization needs.