Comment by alisonatwork

This is something like a "fat binary" with some magic in the header that allows it to run out of the box on Windows and several different UNIXes, a bit like those sneaky shell scripts that run on several platforms[0]. It still needs to include some native code for each of the platforms inside the compiled binary, so it's perhaps better to see it as a slick packaging/distribution solution for C programmers than a total game changer for developers everywhere.

The more interesting thing I think is the mapping of C library functionality between Linux, BSD and Windows. There have been other attempts to do this, but they never seem to get much traction. I think it's because C programmers tend to get wedded to their OS of choice and then invest time in improving that platform's C libraries. The problem with trying to remain portable with everything is that you tend to be stuck working with the lowest common denominator functionality, which can be frustrating when doing OS-specific stuff would open up so many more options.

All that said, the cleverness of this project is inspirational in a way that might encourage other programmers to also focus more on building against simple functionality that is truly portable. It shows that you don't need all the bells and whistles to build cool stuff. That feels aligned with early UNIX philosophy and (more broadly) the hacker ethic, which is why it's neat to see, even if never gets adopted as a mainstream thing.

[0] https://github.com/llamasoft/polyshell