  Many new results on hadron spectra have been appearing in the past few years
thanks to improved experimental techniques and searches in new channels. New
theoretical techniques including refined methods of lattice QCD have kept pace
with these developments. Much has been learned about states made of both light
(u, d, and s) and heavy (c, b) quarks. The present review treats light-quark
mesons, glueballs, hybrids, particles with a single c or b quark, charmonium,
and bottomonium states. Some prospects for further study are noted.
