macOS provides an API called Hypervisor.framework for virtual machine managers like Virtualbox. It means they don't need kernel modules anymore. QEMU also uses it for acceleration.
Is there anything that I can use for running Windows now?
I'm pretty sure Parallels will come up with a solution. If you want to play with virtualizing Windows via Hypervisor.framework right now, I remember that the people from Veertu.com had Windows running via their Veertu Desktop product. But they seem to be focused on virtualizing macOS-on-macOS right now.
Parallels can already use Hypervisor.framework - it's a per-VM configuration option.
Thanks, good information
If you actually mean now, VirtualBox still works. If you want a Hypervisor.framework based system, I think Veertu used to have an app on the App Store.