I came across a site while looking for more GLPK (Gnu Linear Programming Kit) information. The site is Decision Tree for Optimization Software.
Decision Tree for Optimization Software
The site is great information for different types of software related to different types of problem sets such as Linear Programming, Non-linear programming, Multiobjective, Least Squares, etc. One could spend hours on this site alone just trying to draw conclusions for the type of software engine to solve an optimization problem.