Nlopt is a free/open-source library for nonlinear optimization, providing a common interface for a number of different free optimization routines available online as well as original implementations of various other algorithms. its features include:

* callable from c, c++, fortran, gnu octave, python, gnu guile, gnu r.
* a common interface for many different algorithms
* support for large-scale optimization.
* both global and local optimization algorithms.
* algorithms using function values only (derivative-free) and also
algorithms exploiting user-supplied gradients.
* algorithms for unconstrained optimization, bound-constrained optimization,
and general nonlinear inequality/equality constraints.
this package contains the bindings for gnu guile.