Nowadays, with uv (and probably some other tools too) it's pretty easy to ship a python program on a machine that doesn't even have python on it, so it's pretty much a solved problem today (in most cases). But 5 or 10 years ago it was a real hassle that go solved elegantly. Yes you can make python executables but they are like 100 Mb even for a simple hello world. It's a last resort solution.
I don't understand your comment on magic comments. You don't need them to cross-compile a program. I was already doing that routinely 10 years ago. All I needed is a `GOOS=LINUX GOARCH=386 go build myprog && scp myprog myserver:`
> "making a folder" and "putting a ... main() func" in it
You can't do that with python for instance. First, you need a python interpreter on the target machine, and on top of that you need the correct version of the interpreter. If yours is too old or not old enough, things might break. And then, you need to install all the dependencies. The correct version of each, as well. And they might not exist on your system, or conflict with some other lib you have on your target machine.
Same problem with any other interpreted language, including Java and C# obviously.
C/C++ dependency management is a nightmare too.
Rust is slightly better, but there was no production-ready rust 16 years ago (or even 10 years ago).
The biggest source of incompatibility isn't in the programming languages. It's either in the specifications ("hmm maybe one byte isn't enough after all for a character, let's break all those assumptions") or in the hardware ("maybe 16 bits isn't enough of address space").
> When mathematical notation evolves, old proofs do not become obsolete! There is no analogy to a "breaking change" in math.
I disagree. The development of non-euclidean geometry broke a lot of theorems that were used for centuries but failed to generalize. All of a sudden, parallels could reach each other.
> Can we write a family of nested programming languages where core features are guaranteed not to change in breaking ways, and you take on progressively more risk as you use features more to the "outside" of the language?
We could, the problem is everyone disagrees on what that core should be. Should it be memory-efficient? Fast? Secure? Simple? Easy to formally prove? Easy for beginners? Work on old architecture? Work on embedded architecture? Depending on who you ask and what your goals are, you'll pick a different set of core features, and thus a different notation for your core language.
That's the difference between math & programming languages. Everyone agrees on math's overall purpose. It's a tool to understand, formalise and reason about abstractions. And mathematical notation should make that easier.
That being said, the most serious candidate for your "core language guaranteed not to change and that you can build onto" would be ANSI C. It's been there more more than 35 years, is a standard, is virtually everywhere, you can even write a conforming compiler for a brand new architecture, even an embedded microchip very easily, and most of not all the popular languages nowadays are build on it (C++ of course, but also C#, java, javascript, python, go, php, perl, haskell, rust, all have a C base), and they all use a C FFI. I'm not sure ANSI C was the best thing that ever happened to our industry, though.
> There's no reason we can't be writing code that lasts 100 years. Code is just math. Imagine having this attitude with math: "LOL loser you still use polynomials!? Weren't those invented like thousands of years ago? LOL dude get with the times, everyone uses Equately for their equations now. It was made by 3 interns at Facebook, so it's pretty much the new hotness." No, I don't think I will use "Equately", I think I'll stick to the tried-and-true idea that has been around for 3000 years.
Not sure this is the best example. Mathematical notation evolved a lot in the last thousand years. We're not using roman numerals anymore, and the invention of 0 or of the equal sign were incredible new features.