The AgroEcosystem Performance Assessment Tool is a computer program used to evaluate the agronomic and environmental performance of management practices in long-term agroecosystem experiments.  The program employs a simple scoring method to quantify the performance of management practices using indicators grouped within agroecosystem functions.  Management practices are evaluated on a relative basis using the method, thereby internalizing comparisons.  Because of its specialized application to long-term experiments, the program is designed primarily for use by agricultural researchers.