  The suppression of the yield of high transverse momentum $p_{T}$ hadrons in
heavy-ion collisions, referred to as "jet-quenching", has now developed into a
comprehensive science. Jets are now used as probes of a variety of properties
of the dense medium through which they propagate. Major theoretical
improvements include jet modification in a 3-D fluid dynamical medium, the
first set of in-medium Monte-Carlo implementations, an understanding of
multi-hadron observables and energy flow within perturbative QCD, along with
improvements in the AdS/CFT description of energy loss. On the experimental
side, high statistics data are allowing for the first discriminatory test of
various theoretical models and approximations while the new measurements of
full jet reconstruction pose a challenge to theory.
