  A unified theory is outlined for the cuprates, Fe-based, and related
superconductors. Their low-energy excitations are approached in terms of
auxiliary particles representing combinations of atomic-like electron
configurations, and the introduction of a Lagrange Bose field enables their
treatment as bosons or fermions. This theory correctly describes the observed
phase diagram of the cuprates, including the non-Fermi-liquid to FL crossover
in the normal state, the existence of Fermi arcs below T^* and of "marginal-FL"
behavior above it. The anomalous behavior of numerous physical quantities is
accounted for, including kink- and waterfall-like spectral features, the drop
in the scattering rates below T^* and more radically below T_c, and an
effective increase in the density of carriers with T and \omega, reflected in
transport, optical and other properties. Also is explained the correspondence
between T_c, the resonance-mode energy, and the increase in the gap below T_c.
