Hello, I work in the Optimization group at the University of Campinas. Two of my colleagues have written a very good general purpose nolinear optimization solver called Algencan.
It is GPL. I was talking to Ernesto and Mario some time ago about JuMP. I have promised them that I would write a good interface for Algencan for JuMP. So, now that the semester is over I might find out some time in my schedule to start thinking about making this a reality. Can someone point out to me the right documentation for me to start to write the code?