We consider three popular types of shared memory that support one of the following sets of operations: {CAS, read, write}, {LL, SC, VL, read, write}, or {RLL, RSC, read, write}. We present algorithms that, together with Moir's [Moi97], efficiently implement each shared memory above from any of the other two. Our implementations are wait-free and have constant time and space complexity. Thus, concurrent programs developed for one of the above memories can be ported to any other without incurring any increase in time complexity. Further, since our implementations are wait-free, a wait-free concurrent program remains wait-free even after porting.