This is the fork of the libfgsb3 from cran with the following differences: - The return type has changed is is very similar to what optim returns - Allows a direct C/C++ interface through a R registered function, similar to C interface to optim with 2 additional arguments. - Allows adjustment of tolerances for minimization success. - Added xtolAtol and xtolRtol minimization success criterion. - Added maxit termination