This is the summary report of the energy frontier QCD working group prepared
for Snowmass 2013. We review the status of tools, both theoretical and
experimental, for understanding the strong interactions at colliders. We
attempt to prioritize important directions that future developments should
take. Most of the efforts of the QCD working group concentrate on proton-proton
colliders, at 14 TeV as planned for the next run of the LHC, and for 33 and 100
TeV, possible energies of the colliders that will be necessary to carry on the
physics program started at 14 TeV. We also examine QCD predictions and
measurements at lepton-lepton and lepton-hadron colliders, and in particular
their ability to improve our knowledge of strong coupling constant and parton
distribution functions.Comment: 62 pages, 31 figures, Snowmass community summer study 201
