UTM
UTM is a fully featured system emulator and virtual machine host for iOS and macOS. It is based on QEMU. It allows you to run Windows, Linux, and more on your Mac, iPhone, and iPad. 1
It comes with a significant number of preconfigured machines, including Linux distros like ArchLinux, Debian, Fedora, Ubuntu, etc., and even Windows versions ranging from XP to Windows 11. You can also run older operating systems like Sun Solaris or Mac OS 9.
The machines can be configured in just a few simple steps. There's also a way to run these virtual machines on iOS or iPadOS, but it involves a series of cumbersome steps, so I can't comment on that since I've never done it.