LANCELOT. A Fortran package for large-scale nonlinear optimization (Release A). LANCELOT is a software package for solving large-scale nonlinear optimization problems. This book provides a coherent overview of the package and its use. In particular, it contains a proposal for a standard input for problems and the LANCELOT optimization package. Although the book is primarily concerned with a specific optimization package, the issues discussed have much wider implications for the design and implementation of large-scale optimization algorithms.