LINDO is described as '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'. There are four alternatives to LINDO 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 LINDO are lpsolve (Free, Open Source), GNU Linear Programming Kit (Free, Open Source) and Linear Program Solver (Free, Open Source).