  We review recent developments in the QCD description of jet production and
modification in reactions with heavy nuclei at relativistic energies. Our goal
is to formulate a perturbative expansion in the presence of nuclear matter that
allows to systematically improve the accuracy of the theoretical predictions.
As an example, we present calculations of inclusive jet cross sections at RHIC,
Z0/gamma*-tagged jet cross sections at the LHC, and jet shapes that include
both next-to-leading order perturbative effects and the effects of the nuclear
medium.
