  The filled skutterudite compound \PrOsSb{} has been found to exhibit
superconductivity with a critical temperature $T_\mathrm{c} = 1.85$ K that
develops out of a heavy Fermi liquid with an effective mass $m^{*} \approx 50
m_\mathrm{e}$. The current experimental situation regarding the heavy fermion
state, the superconducting state, and a high field, low temperature phase that
is apparently associated with magnetic or quadrupolar order in \PrOsSb{} is
briefly reviewed herein.
