Qeasy is a Mac OS X front-end to the QEMU CPU Emulator (QEMU is a generic and open source machine emulator and virtualizer.
When used as a machine emulator, QEMU can run OSes and programs made for one machine (e.g. an ARM board) on a different machine (e.g. your own PC). ) which can emulate several different flavours of CPU, including x86, ARM, SPARC and PowerPC.