High energy hadron colliders have been the tools for discovery at the highest mass scales of the energy frontier from the SppS, to the Tevatron and now the LHC. This report reviews future hadron collider projects from the high luminosity LHC upgrade
to a 100 TeV hadron collider in a large tunnel, the underlying technology challenges and R&D directions and presents a series of recommendations for the future development of hadron collider research and technology.
