The issues related to the development of a new code for nonstiff differential equations will be discussed. This code is based on the Nordsieck representation of type 1 DIMSIMs, implemented in a variable-step variable-order mode. Numerical results demonstrate that the error estimation employed in the code is very reliable and that the step and order changing strategies are very robust. This code outperforms the ode45 code from Matlab ODE suite for moderate and stringent tolerances. (Joint work with J.C. Butcher and P. Chartier).

MINISIMPOSIUM SESSION: 6. Novel methods for ODEs