Goal: Highly portable (1/3) Flexible endianness and word size: Endian: big, little Word size: ILP32, LP64 All combinations are supported Some CPU families can be either endian (e.g, mipseb, mipsel, sh3el, sh3eb) 64 bit CPUs can run the 32 bit binaries of the same CPU family Application binaries of a CPU family run on all architectures in the same family