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
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."