From Simplex Solver:
Simplex Solver 1.0 optimizes (maximizes or minimizes) a linear objective function Z subject to a number of linear restrictions (first degree equalities and inequalities). After entering the input data press Solve button and move your mouse over tables cells. You will find a visual description of how the numerical values were obtained. Input data can be integers, regular numbers, fractions or a mixture of them. Regular numbers and non-regular numbers are converted to irreducible fractions. Try online Simplex Solver 1.0 to find how the simplex method works.