This volume contains a selection of papers presented at the conference on High Performance Software for Nonlinear Optimization which was held in Ischia, Italy, in June, 1997. The book provides an overview of the nonlinear optimization field, including algorithms, software evaluation, implementation issues, applications, and areas of research, through authoritative papers by some of the most active and well-known researchers in the field. The papers of the Proceedings can be recommended to mathematicians, physicists, and engineers working in the fields mentioned above, as well as recommended for further reading within graduate studies.