I don't see where it has anything to do with Node. It looks like it's using NPM to install it, but the actual running of the VM looks like it goes through the standard hypervisor of the host OS. NPM is technically separate from Node (though yes, the majority of its use is for Node modules). If it is using Node for anything, I can only imagine it is as a replacement for shell scripting.

Interesting, using NPM. Now that I think about it, it's the only package manager that I know of that runs on and is commonly used on all 3 major OSes.