The IndianDragon µ blog ->The Leopard clarification 😉
Leopard OSX 10.5 ->
Is a hybrid OS,i.e it is a 32bit(32bit libs) OS and it can also run 64 bit Apps. An app which is made to run on 64bit environment can run flawlessly on Leopard on the same mode.
Snow Leopard 10.6 ->
Is a pure 64 bit OS (64bit libs) the Apps made for snow leopard are 64bit apps. Snow leopard can also run 32bit Apps in a separate mode called 32bit mode.Under 32 bit mode the whole OS behaves like a 32 bit OS.
But what is the catch? why does Apple need a Snow leopard?
well Snow leo is not just a 64 bit OS,but it includes an array of pathbreaking technologies like Open CL,QuickTime H.264 hardware acceleration support etc. I hope the developers make use of these and build more efficient coding practices for all future OS’s