Buy once, use forever A directory of one-time purchase software

Unless it's (maybe) mainfraame software, your software is going to break with an OS update. O you can maybe keep it working for a while in a VM, but the idea that you'll keep a software binary working forever is, for practical purposes, mostly silly.

Is it? I'm pretty sure Rollercoaster Tycoon 1 continued to function on Windows Vista (released some ten years after the game) and in Windows 7 everything besides saving worked, and iirc there was a trick for that as well. These things can last a long time

Weird example perhaps but that's one of the oldest totally unmaintained things I used back in my Windows days. WINE may also be a way to run older Windows wares without needing a whole VM setup

On Android, I also use software written for Android 4 on Android 10 without problems. The permission model got more strict so it asks you for giving some blanket permissions because those weren't granular at that SDK/API version (iirc network and storage access are two of the three main ones), but after that one-time confirmation it works perfectly, and from f-droid I also trust that it doesn't abuse these permissions

Of course, there's also plenty of counterexamples. GOG exists for a reason, patching up games to run on modern OSes. I guess it's a risk but I don't generally expect most things to break with every version upgrade

Windows and Android are OK to pretty good when it comes to backward compatibility.

MacOS Software sadly does break sometimes.

It's called open source - I'm confident in 30 years time there will still be a vim port to whatever OS is in vogue.

Windows backward compatibility counter example: Paint Shop Pro 7.04 still works great here after almost a quarter century.

Port is the operative word there.

Proprietary binaries may work but there's no guarantee depending upon how the software was written.

Microsoft generally strives for pretty good backward compatibility. Especially for, relatively speaking, simpler software.

Somewhere buried on the Microsoft site there is a page that says they are committed to getting any 32bit windows software or above working and they have a separate support team for. I assume they are the Compatibility team.

End of the day I don't care if it's same binary or not, i just want my apps and tooling to work the way they have always worked.