DNOPT (dense nonlinear optimizer) is Fortran 77 software developed by Prof Philip Gill and Elizabeth Wong (UC San Diego) and Prof Michael Saunders (Stanford).
SQOPT is a software package for solving large-scale linear and quadratic programs. The quadratic objective function may be positive definite or semidefinite (convex). Efficiency is best if many constraints are active at a solution.
SNOPT is a software package for solving large-scale optimization problems (linear and nonlinear programs). It employs a sparse SQP algorithm with limited-memory quasi-Newton approximations to the Hessian of Lagrangian.
NPSOL is a software package for solving constrained optimization problems (nonlinear programs). It employs a dense SQP algorithm and is especially effective for nonlinear problems whose functions and gradients are expensive to evaluate.
LSSOL is a software package for solving constrained linear least-squares problems and convex quadratic programs (definite or semidefinite), including linear programs. Dense matrices are assumed throughout.
QPOPT is a software package for solving dense linear and quadratic programs. If the quadratic objective function is convex (definite or semidefinite), the solution obtained is a global optimum.