  In this summary report of the 2001 Snowmass Electroweak Symmetry Breaking
Working Group, the main candidates for theories of electroweak symmetry
breaking are surveyed, and the criteria for distinguishing among the different
approaches are discussed. The potential for observing electroweak symmetry
breaking phenomena at the upgraded Tevatron and the LHC is described. We
emphasize the importance of a high-luminosity $e^+e^-$ linear collider for
precision measurements to clarify the underlying electroweak symmetry breaking
dynamics. Finally, we note the possible roles of the $\mu^+\mu^-$ collider and
VLHC for further elucidating the physics of electroweak symmetry breaking.
