When I was at Apple in the mid-90's with access to the (obviously pre-NeXT) MacOS source code, I was amazed at how many of these version checks were in the code

When I was at Apple in the mid-90's with access to the (obviously pre-NeXT) MacOS source code, I was amazed at how many of these version checks were in the code; there were always a lot of Microsoft app/version checks in there.