I need a nonlinear solver for optimizing a given function. I tried the inbuilt solvers for Excel and OpenOffice. The problem is Excel gives me only the local maximal and not the global one. OpenOffice has a very small step and take too much time.

I'll give a try to Matlab's "Global Optimization Toolbox". I dont know if it could take more than 2 variables.

Please if you know a good solver/optimizer gimme a shout. Thanks in advance