In a C++ application I'm coding, I need to solve a system of non-linear equations (N equations, N unknowns).
The systems I'm solving will be rather small (up to 10 equations/unknowns), so performance is not going to be a real issue. I've searched the web a bit for a non-linear solver library, and I couldn't get to something which looks easy to use (got to NOX and C/C++ Minpack, but both seem to be an overkill for my need).
Any thoughts and ideas of easy-to-use libraries for this purpose?