That actually seems fairly interesting and unusual—in Linux terms, Windows NT (and its progeny) started with the moral equivalent of the x32 ABI[1] on its only

That actually seems fairly interesting and unusual—in Linux terms, Windows NT (and its progeny) started with the moral equivalent of the x32 ABI[1] on its only 64-bit architecture (Alpha) and only afterwards introduced support for true 64-bit apps. Which is very reasonable! [1] https://sites.google.com/site/x32abi/ https://sites.google.com/site/x32abi/