NOX and LOCA are a combined package for robustly solving and analyzing large-scale systems of nonlinear equations. NOX is short for Nonlinear Object-Oriented Solutions, and its objective is to enable the robust and efficient solution of the equation: , where using globalized Newton methods such as line search and trust region methods. NOX is designed to work with any linear algebra package and to be easily customized. NOX is part of Sandia’s Trilinos project.