The PoleStar System provides a flexible and user-friendly framework for building and assessing alternative development scenarios at regional, national, and global scales. It is an adaptable accounting and model-building framework designed to assist the analyst engaged in sustainability studies—not a rigid model reflecting one particular approach to environment and development interactions. With PoleStar, analysts can customize data structures, time horizons, and spatial boundaries—all of which can be expanded or altered easily. They can also introduce new variables, indicators, and relationships to match their needs. The system can synthesize information generated from formal models, existing studies, or any other sources upon which the user wishes to draw.