Let's say I wanted to have many different OS's installed on a machine(OSX,BSD,Linux,Winblows because why not) rather than figure out a way to boot all of them and get them to work in harmony(which I believe would be rather difficult with potential for fuck-ups later) is there an 'OS' for virtuallizing all of these? with hardware acceleration support?(say if I wanted to play some games on windows)

I do enjoy my bspwm setup and virtualbox messing around, but sometimes I want a little more to dick around with.

Thanks,
Neeasade

You might want to read about KVM https://en.wikipedia.org/wiki/Kernel-bas...al_Machine. It's a bit related.

You could also check out QubesOS, which is created for a scenario like that.

As venam stated, your best choice here is KVM, using qemu has a manager for it.
If all you need is a bunch of linux based machine, you might also go with LXC, though it can be a bit hard tricky to create self-contained templates at first (eg, the default debian template relies on the "debootstrap" utility, which has to be avail on your host system).

My experience with LXC is that it's cool when it's working, but it turns to a nightmare once something stops working, especially in the network. Want to fix it? Prepare your altar for the sacrifice of a virgin and never forget to continously throw up gang signs! (Something it has apparently inherited from it's de-facto predecessor, OpenVZ.) Using LXC would also limit you to use the kernel of the host system, since it's containerization, not virtualization.

Gaming in a virtual machine requires the ability to pass-through PCI. Xen and KVM both support that, with a catch - you need a second graphics card, because the one dedicated to the virtual machine is unusable for the host system. I only dabbled with it shortly, worked pretty well while using a GT640 for the host and a GTX980 for the virtual machine. I found this in my bookmarks, maybe it helps.

I would go with KVM. It's deeply integrated into most Linux distributions, has awesome management tools such as virt-manager, all while being easily scriptable.

kvm+qemu it really is the best solution out there it can even run obscure os like plan9, and templeos

I would just install a minimal distro and use VirtualBox.

Lots of new virtualization and container tech has come out since 2016. Which one do you use, in which scenario, recommend, or have comments on?

From docker, vagrant, containerd, lxc, lxd, openvz, QEMU, OpenBSD vmm, etc..

maybe it is a bit too "fat" for your liking, but what i liked for testing a lot of different systems is proxmox[1]
you can also run it (instead of a headless server install) just as a normal operating system as well. In the end it boils down to KVM/QEMU. It is pretty nice to work with and you can passthrough your GPU to a specific VM if you like. For some time i used a raspi4 as a thin client and connected via SPICE to my vm's with shared storage it was pretty nice to work with.


[1] https://www.proxmox.com

Doing Docker, but wrong:
https://antranigv.am/weblog_en/posts/2021-08-13-13-37/