It is easier than you think. First, we get rid of PATH= inside scripts. A lot of incompatibilites comes from /bin, not the shell itself. Treat executables like

It is easier than you think. First, we get rid of PATH= inside scripts. A lot of incompatibilites comes from /bin, not the shell itself. Treat executables like services, rewrite everything (reasonable) in pure shell. The scenario I'm trying to prevent is "I want to cut a string in OSX but I wrote for a GNU executable and the syntax is slightly different". Most shell one liners can be rewritten as good quality portable code. If you take just Debian, there are 5 or 6 shells available via apt. These should run wherever Debian runs (x86, arm, hurd, whatever). You can't write a reasonable JavaScript that runs on JScript.exe (it still exists), Apple JXA, gjs and node.js. But you _could_, the language is stable enough, for long enough, that everyone knows how to feature detect the shit out of everything js related. For the shell though, we don't even have a solid list of things that work or not in each shell, or differences across core utilities. Something like caniuse.com, but for UNIX shells, not browsers. Having a page that runs on all browsers was once something impractical and idealistic. Not using tables and invisible 1x1 pixels for layouts was once idealistic. We fixed it though. Mostly.