GNU R package for interface to NLopt

 The nloptr package provides an R interface to NLopt. 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. See
 http://ab-initio.mit.edu/wiki/index.php/NLopt_Introduction for more
 information on the available algorithms.