Bare minimum portabilty?
========================

Which platforms to support? How to decide?

What Hare supports
------------------

- Free OS:es only
- x86_64, aarch64, riscv64

A pragmatic way
---------------

- Linux and Windows
- x86_64 and aarch64
- Maybe Javascript and/or WASM+WASI

What F/OSS distributions supports
---------------------------------
(this is 8(!) arches, not counting the "arm32" variations)

    A = Alpine ("Standard" edition, v. 3.22.1)
    D = Debian 13 "trixie"
    F = Fedora

- aarch64     [ADF]
- armel       [ D ]
- armvhf      [ D ]
- armv7       [A  ]
- loongarch64 [A  ]
- ppc64el     [ADF]
- riscv64gc   [ D ]
- s390x       [ADF]
- x86         [A  ]
- x86_64      [ADF]

The "device count" way
----------------------
(= which have the most devices that are standardized enough
and allow practical installation of 3rd party software)

- Linux and Windows
- aarch64, armhf (or whatever rpi1 is using), i386, x86_64
- Maybe Javascript and/or WASM+WASI

The F/OSS- and OSHW-only way
----------------------------
This is going to very seriously limit the number of users :P

- Free OS:es only
- Free CPU architectures only:
  mrisc32, or1k, ppc64/ppc64le, riscv32/64, sparc64


How to keep code generation easy to port
========================================

The way to get most portability is to compile to C, but that makes cross-
compilation cumbersome, since it requires a C compiler toolchain and a
corresponding sysroot.

The ABI must be implemented in full regardless, for two reasons:

1. For ABI stability over time, even as the code generator gets improved.
2. For interopability with C code.

There could be multiple "mixins" for the code generator. Maybe some really
simple (but unoptimized) one. E.g. all operations could go through a
register.