Half of these exist because I was bored once.
The Windows 10 and MacOS ones are GPU passthrough enabled and what I occasionally use if I have to use a Windows or Mac application. Windows 7 is also GPU enabled, but is more a nostalgia thing than anything.
I think my PopOS VM was originally installed for fun, but I used it along with my Arch Linux, Debian 12 and Testing (I run Testing on host, but I wanted a fresh environment and was too lazy to spin up a Docker or chroot), Ubuntu 23.10 and Fedora to test various software builds and bugs, as I don’t like touching normal Ubuntu unless I must.
The Windows Server 2022 one is one I recently spun up to mess with Windows Docker Containers (I have to port an app to Windows, and was looking at that for CI). That all become moot when I found out Github’s CI doesn’t support Windows Docker containers despite supporting Windows runners (The organization I’m doing it for uses Github, so I have to use it).
If I could get vbox to work* on my laptop or find the drive to learn QEMU, then I would have plenty on there. For now I’m just stuck with plenty on my desktop running win10.
*I have installed it a few times on my Debian based distro, but I swear every time I do nothing to it and it destroys itself. Works fine one day, then the next I turn on my laptop, after the only changes being that I created and ran a VM and it decided to hate me and not even boot the program. I think I’m just cursed.
What about Virt Manager GUI, which is what I use here? It’s a frontend for QEMU and it’s not that difficult, honestly.