FILTRANE, a Fortran 95 filter-trust-region package for solving nonlinear feasibility problems Nick Gould and Philippe L. Toint Report 03/17 This paper describes the algorithm and performance of FILTRANE, a new Fortran 95 packages for finding vectors satisfying general sets of nonlinear equations and/or inequalities. A number of algorithmic variants are discussed and extensively compared on a set of CUTEr test problems, indicating that the default variant is both reliable and efficient. This discussion provides a first experimental study of the parameters inherent to filter algorithms.