[fireant911]

One program that I have used extensively is OpenSolver. For those that do linear optimization problems, this is an amazing tool. It works with Microsoft Excel and unlike the standard solver that comes with Excel (that is limited to only 200 decision variables), OpenSolver has NO constraints on the number of decision variables (the limiting factor is the amount of memory on your computer). I regularly run the program with 12K+ variables and 600+ constraints to find an optimal solution to very complex scheduling-type problems. OpenSolver was developed and is maintained by the department of Engineering Science in Auckland, New Zealand.