  This Resource Book reviews the physics opportunities of a next-generation
e+e- linear collider and discusses options for the experimental program. Part 4
discusses options for the linear collider program, at a number of levels.
First, it presents a broad review of physics beyond the Standard Model,
indicating how the linear collider is relevant to each possible pathway. Next,
it surveys options for the accelerator and experimental plan, including the
questions of the running scenario, the issue of one or two interaction regions,
and the options for positron polarization, photon-photon collisions, and e-e-
collisions. Finally, it reviews the detector design issues for the linear
collider and presents three possible detector designs.
