GLPK is a set of routines written in ANSI C and organized in the form
of a callable library. This package is intended for solving large-scale
linear programming (LP), mixed integer linear programming (MIP), and
other related problems.

GLPK includes the following main components:

* implementation of the primal/dual simplex method;

* implementation of the primal-dual interior point method;

* implementation of the branch-and-bound procedure (based on the dual
  simplex method);

* application program interface (API);

* GLPK/L, a modeling language intended for writing LP/MIP models;

* GLPSOL, a stand-alone program intended for solving LP/MIP problems
  either prepared in the MPS format or written in the GLPK/L modeling
  language.

Homepage:
https://www.gnu.org/software/glpk/glpk.html
