Versatile Commodore Emulator
VICE is an emulator collection which emulates the C64, the C64-DTV, the C128, the VIC20, practically all PET models, the PLUS4 and the CBM-II (aka C610). It runs on Unix, MS-DOS, Win32, OS/2, Acorn RISC OS, BeOS, QNX 6.x, Amiga, GP2X or Mac OS X machines.
LayerFS is a RISC OS image filing system. A LayerFS directory constructs itself from several source directories, where objects in the 'lower' directories are overlaid by objects of the same name in the 'higher' directories.