NLopt is a library for nonlinear local and global optimization, for functions with and without gradient information. It is designed as as simple, unified interface and packaging of several free/open-source nonlinear optimization libraries. The latest version and a complete manual may be found at the NLopt home page: http://ab-initio.mit.edu/nlopt It is compiled and installed with the standard GNU autoconf/automake commands: ./configure make make install (See './configure --help' or the INSTALL file for other options.) Once it is installed, #include in your C/C++ programs and link it with -lnlopt -lm. You may need to use the C++ compiler to link in order to include the C++ libraries (which are used internally by NLopt, even though it has a C API). The minimization function, nlopt_minimize, is described in the man page (api/nlopt_minimize.3, which is installed by 'make install'. Interfaces for other languages may be added in the future.