LPI is an interactive linear programming (L.P.) package designed primarily for instructional usage with the Cambridge Monitor System on the IBM/360 Computer. LPI removes the computational burden from the student without depriving him of the decision-making processes necessary for the successful solution of a L.P. LPI is self-instructing as to its own use; a minimum of CP/CMS commands are required to interface the student with LPI. LPI will allow primal simplex and/or dual simplex pivoting; sensitivity analysis of the 'cost' coefficients and the 'requirement' coefficients; the Separable Programming Algorithm; and the Wolfe Quadratic Programming Algorithm.