1. R/GNU Linear Programming Kit Interface - GLPK is an open source software for solving large-scale linear programming (LP), mixed integer linear programming (MILP) and other related problems. Rglpk provides a high level interface to R for solving LP/MILP problems.
3. limSolve - Functions to solve linear inverse models (lim), i.e. find the minimum/maximum of a linear or quadratic function subject to equality and inequality constraints, functions to randomly sample lims.