This is more like Chromium sandboxing, where all of the API calls are hooked in userspace. Not anything involving "virtualization" as we use the term today
Wondered the same. Very confusing if they are unrelated.
If the C 2004 at the bottom is to be believed, it predates VirtualBox by Oracle nee Sun nee Innotek by a few years.
Looks like "Enigma Virtual Box" was first released in October of 2010: