  Kamihara and coworkers' report of superconductivity at Tc = 26 K in
fluorine-doped LaFeAsO inspired a worldwide effort to understand the nature of
the superconductivity in this new class of compounds. These iron pnictide and
chalcogenide (FePn/Ch) superconductors have Fe electrons at the Fermi surface,
plus an unusual Fermiology that can change rapidly with doping, which lead to
normal and superconducting state properties very different from those in
standard electron-phonon coupled 'conventional' superconductors. Clearly
superconductivity and magnetism/magnetic fluctuations are intimately related in
the FePn/Ch - and even coexist in some. Open questions, including the
superconducting nodal structure in a number of compounds, abound and are often
dependent on improved sample quality for their solution. With Tc values up to
56 K, the six distinct Fe-containing superconducting structures exhibit complex
but often comparable behaviors. The search for correlations and explanations in
this fascinating field of research would benefit from an organization of the
large, seemingly disparate data set. This review attempts to provide an
overview, using numerous references, with a focus on the materials and their
superconductivity.

Superconductivity