I don't really understand how ARC works, but I can tell you it's tied into the OS somehow. ARC does partially work on Snow Leopard, but only for 64-bit, and it

I don't really understand how ARC works, but I can tell you it's tied into the OS somehow. ARC does partially work on Snow Leopard, but only for 64-bit, and it's limited (namely, you can't use weak references).