  We report the observation, in Monte Carlo simulations, of a novel type of
quantum ordered state: {\it the metallic superfluid}. The metallic superfluid
features ohmic resistance to counter-flows of protons and electrons, while
featuring dissipationless co-flows of electrons and protons. One of the
candidates for a physical realization of this remarkable state of matter is
hydrogen or its isotopes under high compression. This adds another potential
candidate to the presently known quantum dissipationless states, namely
superconductors, superfluid liquids and vapours, and supersolids.
