This simulator plots a linear demand curve against a linear supply curve and marks the point where quantity demanded equals quantity supplied — the market-clearing equilibrium. A per-unit tax or subsidy drives a wedge between the price buyers pay and the price sellers receive, shifting the effective supply curve and shrinking or reallocating the shaded consumer and producer surplus regions. A separate "Run" button demonstrates tâtonnement: instead of solving the equations directly, an auctioneer starts at an arbitrary price and repeatedly adjusts it toward equilibrium based on observed excess demand or supply, visualising how a market can converge on the right price through trial and error alone.