Resources for Solving Non-linear Optimization Problems

Decision Tree Optimization Software
     Classification of optimization problems and links to solver software by
     Hans D. Mittelmann and P. Spelluci

DONLP
     Code for minimization of a (non-linear) differentiable real function subject
     to (non-linear) inequality and equality constraints, by P.  Spellucci

NLPQLP
     Nonlinear Programming for Parallel Computing, a special (FORTRAN)
     implementation of a sequential quadratic programming (SQP) method
     for distributed computing systems, by K. Schittkowski

Nonlinear Programming FAQ
     List of Frequently Asked Questions on Nonlinear Programming problems
     and software, initiated by John W. Gregory