Google's software suite for combinatorial optimization
Google Optimization Tools, also known as OR-Tools is an open-source, fast and portable software suite for solving combinatorial optimization problems. These encompass problems in vehicle routing, flows, integer and linear programming, and constraint programming. This suite contains a number of solvers, namely: a constraint programming solver; a linear programming solver; wrappers for commercial solvers (like Gurobi or CPLEX) and other open source solvers (SCIP, GLPK, etc.); among others...
An easy and flexible mathematical programming environment for Python.
PyMathProg is a Python reincarnation of AMPL and GNU MathProg modeling language, implemented in pure Python, connecting to GLPK via swiglpk. Create, optimize, report, change and re-optimize your model with Python, easily integrate database, plotting, etc.
PuLP: An LP modeller in Python PuLP is an LP modeller written in python. PuLP can generate MPS or LP files and call GLPK, COIN CLP/CBC, CPLEX and XPRESS to solve linear problems.