Since the discovery by the author and collaborators of superconductivity in the first truly layered compound, TaS2(pyridine)1/2, there have been many types of layered superconductors. These include the graphite intercalation compounds, the transition metal dichalcogenides, the intercalated transition metal dichalcogenides, the organic layered superconductors, the high-temperature cuprates, the various types of artificial multilayers, strontium ruthenate, magnesium diboride, the ternary intermetallics, the quaternary intermetallics or borocarbides, the iron pnictides and oxypnictides, the iron...