Muon Colliders

After an introduction, the projected performances are presented for muon colliders with a range of energies from 126 GeV (the Higgs mass) to 6 TeV. Estimates of potential wall power consumption are also given. It is noted that a merit factor, the number of simultaneously operated detectors times the luminosity divided by the power consumption, rises rapidly above 1.5 TeV. At 6 TeV it is projected to be almost two orders of magnitude higher than that for an e+e- linear collider. The reason for this is discussed. The physics potential of these machines is then outlined, including the 126 GeV collider's unique ability to measure the Higgs width, and the potential for a high energy machine's study of any structure seen in a hadron collider. The design and simulations of the different components are then reviewed, followed by a discussion of the supporting experiments and technology R&D.