A Comparative Study of Computer Programs for Integrating Differential Equations A study comparing the performance of several computer programs for integrating systems of ordinary differential equations is reported. The integration methods represented include multistep methods (predictor-correctors), single-step methods (Runge-Kutta) and extrapolation methods (both polynomial and rational). The testing procedure is described together with the evaluation criteria applied. A set of test problems on which the programs were tested is included in an appendix. For the particular problems and criteria used in the investigation it was found that a program based on rational extrapolation showed the best performance. CACM November, 1972 Fox, P. ordinary differential equations, integration, program comparison, certification, validation 5.10 5.17 CA721101 JB January 27, 1978 2:45 PM 2268 5 2268 2268 5 2268 2268 5 2268 2567 5 2268 2268 6 2268 755 6 2268