GNU Linear Programming Kit is described as 'The GLPK (GNU Linear Programming Kit) package is intended for solving large-scale linear programming (LP), mixed integer programming (MIP), and other related problems'. There are four alternatives to GNU Linear Programming Kit for Windows, Linux and Mac. The best alternative is GUSEK (GLPK Under Scite Extended Kit), which is both free and Open Source. Other great apps like GNU Linear Programming Kit are lpsolve (Free, Open Source), Linear Program Solver (Free, Open Source) and LINDO (Freemium).
Classic LINDO's simple interface and straightforward model expression style make it easy to learn and use. Classic LINDO is appropriate for building and solving moderately sized linear and integer models.