Everyone is using llama.cpp because we reject the idea of giving up on system libraries like nix does. That kind of tomfoolery (at least in the desktop context) is only required when you use software projects that use libraries/languages which break forwards compatibility every 3 years.

If you just write straight c++ (without c++xx, or anything like it) you can compile the code on machines from decades ago if you want.

Docker. Don't forget Docker. I pretty much checked out the day using it became a requirement just to talk to a GPU and didn't do much with machine learning until llama.cpp came along.

What's c++xx?

C++11, and greater.

Huh, I was proficient in Rust before "properly" learning C++, so maybe that accounts for it, but I didn't realize C++11 was controversial. Is it just move semantics, or are there some library things that are hard to implement?

I think what OP is saying is that decades-old systems wouldn't have C++11-compatible compilers on them.

And maybe that "C++" is now basically a bunch of different incompatible languages instead of just 1 language, depending on what "xx" is (11, 14, 17, 20, 23, etc).

It's like Python 2 vs Python 3 except even worse.

In my experience, C++03 code works just fine without changes on a C++11 and C++14 compilers, so no, it's not at all like Python 2/3. The few features that were ripped out were exactly the stuff that pretty much no-one was using for good reasons (e.g. throw-specifications).