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 a versatile emulator for x86 architecture that provides high configurability but has performance limitations, making it suitable for development and testing. In contrast, Xen is a robust Type-1 hypervisor designed for efficient virtualization with strong isolation, making it ideal for production environments.