Comment by packetlost

> One can dream of a future where perhaps it will be possible to write a function, library, or program in any language one chooses and call it from any other shell or language without swig or ceremony

I mean, there's a reason text was selected, it's the lowest common denominator. What you're asking for is universal FFI, which we already have that for the most part: C. The problem ultimately turns into runtime and resource management issues when crossing language boundaries, that is, unless you use OS primatives (pipes, sockets, shared memory, processes, etc.) and use message passing/pipelines exclusively. Then we're back to plaintext.

There's a ton of non-printable characters in ASCII that are useful as delimiters for non-keyboard interactive programs that are largely vestigial. One could at least consider reusing them for delimiters and special control sequences for message passing, but without some sort of standardization it's limited in practical use.