I really like UTM's business model: identical free software if you want it, or 10 bucks if you want automatic updates and to fund UTM development.

I didn't realize UTM was open source, so I followed a few guides for setting up VMs directly with libvirt: https://n8henrie.com/2022/09/linux-vms-on-my-m1-mac/

Having since learned that they are open source I think I'll look into UTM again, but even as a novice I didn't find it too difficult to use libvirt.

The only problem seems to be that it won't allow you to run an earlier OS X that can still run 32-bit programs.

The comment you replied to was about UTM, which does allow running earlier versions of macOS/OS X on Apple silicon hosts:

Virtualizing OpenCore and x86 macOS on Apple Silicon (and even iOS!) https://khronokernel.github.io/apple/silicon/2021/01/17/QEMU...

Run Tiger, Leopard, or any Mac OS X PowerPC version on M1 https://tinyapps.org/docs/tiger-on-m1.html

Their website says differently Note that macOS VM support is limited to ARM based Macs running macOS Monterey or higher. https://mac.getutm.app/

> Their website says differently Note that macOS VM support is limited to ARM based Macs running macOS Monterey or higher.

While ARM virtual machines are limited to Monterey and higher on Apple silicon[0], emulation works just fine for x86, PowerPC, etc.

Here's a video I cobbled together of UTM running Tiger on an Apple silicon Big Sur host: https://tinyapps.org/screenshots/tiger-on-m1.mp4

and another of the same host running Windows XP: https://tinyapps.org/screenshots/20210522-utm-xp.mp4

[0] https://kb.parallels.com/125561 "To run a macOS Monterey VM on Mac computers with Apple M1 chips, Parallels Desktop 17 uses new technology introduced in macOS Monterey, that's why it is not possible to run earlier versions of macOS on a Mac with Apple M1 chips."

That means that the host has to be on Monterey or higher. The guest can be any macOS version.

No, the guest (if using Virtualization) must be Monterey or higher as well.

Those earlier macOS versions don't have the frameworks to run virtualisation with. There are some hacks (mackintosh-ish) that allow you to run very old Intel releases on non-ARM releases, those virtualise the CPU but emulate nearly everything else.

Another problem is that it's not programmatic (e.g., like Vagrant), so it's tiresome to spin up/down a bunch of VMs.

There are several tools to create VMs from the CLI or scripts like QEMU, docker machine, and podman machine.