Object-oriented solvers for initial value problems. The Godess (generic ordinary differential equations solving system) project aims at the development of an object-oriented solver for initial value problems. In this project, the use of object-oriented techniques has been instrumental in development, testing, evaluation and verification of methods and control strategies. Based on comparisons with traditional solvers, we find that Godess is competitive with respect to accuracy and computational speed. These experiments demonstrate that this very generic solver is of real practical value.