OpenSolver

OpenSolver extends Excel Solver models with selectable engines and highlights objective, decision variables and constraints on the sheet, marking integer/binary variables. In the documented CBC workflow it extracts the worksheet model into a file, solves it and automatically loads results back into the spreadsheet. The linearity checks are partial; the modeller must ensure the chosen linear solver fits the formulas. QuickSolve reuses an initialized model while specified parameter cells change, assuming their effect on constraint right-hand sides is linear. There is no artificial model-size cap, but memory and solve time remain limits. Its published API distinguishes optimal, infeasible, unbounded and limited-suboptimal status; retain that status with any result. The Sheets route is separate from the Excel add-in.