VICE is a program that runs on a Unix, MS-DOS, Win32, OS/2, BeOS, QNX 4.x, QNX 6.x, Amiga, Syllable or Mac OS X machine and executes programs intended for the old 8-bit computers. The current version emulates the C64, the C64DTV, the C128, the VIC20, practically all PET models, the PLUS4 and the CBM-II (aka C610/C510). An extra emulator is provided for C64 expanded with the CMD SuperCPU.
VICE has been used by a few sysops to setup a commodore 64 BBS.
Visit the VICE website to read more about it