It was not clear from early work in optimality theory how the theory could attack the rich range of phenomena now found in segmental alterations. However, there is now a body of work that concentrates on working out the details of featural phonology with OT, demonstrating that the theory allows superior explanations of the typological possibilities and the underlying motivations for these phenomena. This volume brings together current work by some of the influential researchers in this area, ranging from the authors of recent influential dissertations to prominent senior faculty.