You learned wrong. CoreOS is a derivative of Chromium OS, which uses Portage as its package manager. Simply typing "emerge" into a window does not Gentoo make,

You learned wrong. CoreOS is a derivative of Chromium OS, which uses Portage as its package manager. Simply typing "emerge" into a window does not Gentoo make, which is a bummer, because it shows a lack of research on the part of the author (that really came out in other areas, too). It's also largely irrelevant, because CoreOS should in practice be read-only when you boot it, and you're not extremely concerned with the details of how it's put together (which its usage of Portage is).