  In this review, the authors present a summary of experimental reports on
newly discovered iron-based superconductors as they were known at the end of
2008. At the same time, this paper is intended to be useful for experimenters
to know the current status of these superconductors. The authors introduce
experimental results that reveal basic physical properties in the normal and
superconducting states. The similarities and differences between iron-pnictide
superconductors and other unconventional superconductors are also discussed.
