  This chapter discusses the equilibrium crystal shape (ECS) from a physical
perspective, beginning with a historical introduction to the Wulff theorem. It
takes advantage of excellent prior reviews, particularly in the late 1980's,
recapping highlights from them. It contains many ideas and experiments
subsequent to those reviews. Alternatives to Wulff constructions are presented.
Controversies about the critical behavior near smooth edges on the ECS are
recounted, including the eventual resolution. Particular attention is devoted
to the origin of sharp edges on the ECS, to the impact of reconstructed or
adsorbed surface phases coexisting with unadorned phases, and to the role and
nature of possible attractive step-step interactions.
