OPAL is a tool for quantifying the impacts of development and the value of potential protection or restoration activities to biodiversity and ecosystem services.  OPAL helps identify mitigation options that can restore ecosystem service benefits back to the same people affected by a development project and tracks the amount of mitigation needed to meet biodiversity and ecosystem service mitigation targets. OPAL combines widely available ecological and social data along with the Natural Capital Project’s spatially explicit InVEST ecosystem service models to recommend offset parcels based on flexible, user-defined criteria.