OS X supported OS9 apps until long after people were puking at the mere sight of OS9 apps.

And when they converted to Intel, they also provided Rosetta, a completely ridiculous binary translation system to make PPC apps work.

Those are bad examples.

The most striking for me when Jobs announced move to Intel was the bit where he told that they had OS X builds for Intel since the very first version of OS X. Who knows what are they cooking in their secret kitchens.

Motorola 68k -> Apple/Motorola/IBM PowerPC -> Intel ???