Using ANDF you could produce portable binaries that would run on any UNIX system, regardless of CPU architecture. It was never commercially released though. I think while it is cool technology the market demand was never really there. For a software vendor, recompiling to support another UNIX isn't that hard; the real hard bit is all the compatibility testing to make sure the product actually works on the new UNIX. ANDF solved the easy part but did nothing about the hard bit. It possibly would even make things worse, because then customers might have just tried running some app on some other UNIX the vendor has never tested, and then complain when it only half worked.
Standards are always going to have implementation bugs, corner cases, ambiguities, undefined behaviour, feature gaps which force you to rely on proprietary extensions, etc. That's where the "hard bit" of portability comes from.
See https://en.wikipedia.org/wiki/Architecture_Neutral_Distribut...
Using ANDF you could produce portable binaries that would run on any UNIX system, regardless of CPU architecture. It was never commercially released though. I think while it is cool technology the market demand was never really there. For a software vendor, recompiling to support another UNIX isn't that hard; the real hard bit is all the compatibility testing to make sure the product actually works on the new UNIX. ANDF solved the easy part but did nothing about the hard bit. It possibly would even make things worse, because then customers might have just tried running some app on some other UNIX the vendor has never tested, and then complain when it only half worked.
Standards are always going to have implementation bugs, corner cases, ambiguities, undefined behaviour, feature gaps which force you to rely on proprietary extensions, etc. That's where the "hard bit" of portability comes from.