My current research focuses on the implementation of BASBL (Branch-And- Sandwich BiLevel) solver for nonlinear bilevel problems. BASBL is implemented in C++ within the MINOTAUR toolkit (developed at Argonne National Laboratory) and is based on the recent Branch-and-Sandwich algorithm (Kleniati and Adji- man, J. Glob. Opt. 60, 425–458, 2014) which is capable of solving very general nonconvex bilevel problems.
BASBL homepage: http://basblsolver.github.io/home/