alt Hacker NewsCorrect. Apple's licensing requires macOS to run on Apple hardware, and limits you to 2 concurrent macOS VMs per host. This is enforced by the Apple Vz framework itself. Some KVM-based solutions bypass these checks, but they aren’t compliant for production use.
There’s instead no such limitation when running Linux VMs on a macOS host.
I'm pretty sure the requirement is that the hardware is an Apple Mac, I don't remember macOS being your Hypervisor a requirement. ESXI supports running macOS on Apple Hardware (it extracts the key from the SMC).