Making macOS version of windows source code

  .app, compilation, exe, macos, windows

I apologize if this is a duplicate. I did search to see if there was a similar question but the only one I could find is somewhat specific to his project and I am looking for something more general.

I keep finding programs that are exactly what I’m looking for, but the programmer only made a windows version. I am a fairly new programmer myself and most of my training is in making web apps so I am not used to making something that works independently of a browser but would like to learn. Rather than complain about it, I’d like to be able to work with some of these software creators to turn their great program into one for both OSs. I can’t seem to find any info on this anywhere though. I know some very basic things only need recompiled on the other OS but I feel like bigger more complicated software needs more than just that. All I can find when I try to search though gives me apps to make windows exes run on macs which I have had mixed experiences with in the past.

Source: Windows Questions