QubesOS has a thing where you can run a program inside a virtual machine, and instead of getting an entire GUI of the VM, what shows up on the screen is the program itself, indistinguishable from programs run from other VMs.
Is this sort of technology available/applied anywhere else? Could I get something similar on my Linux Mint box, for example?
@cirno QubeOS is an hypervisor, think like an vmware ESXI running several vms. You can do similar with, let's say, virtualbox. Or you can make your own with libvirt/kvm/qemu. So yes, it's doable, but same as QubeOS, there's a huge performance penalty.