  Ideas about a duality between gauge fields and strings have been around for
many decades. During the last ten years, these ideas have taken a much more
concrete mathematical form. String descriptions of the strongly coupled
dynamics of semi-realistic gauge theories, exhibiting confinement and chiral
symmetry breaking, are now available. These provide remarkably simple ways to
compute properties of the strongly coupled quark-gluon fluid phase, and also
shed new light on various phenomenological models of hadron fragmentation. We
present a review and highlight some exciting recent developments.
