Conclusions

I have consolidated my modules for acoustic nd elastic 2D and 3D modeling and migration algorithms. Their numerical behaviour closely resembles the mathematical formulas. These building blocks can be put together in many different variations. Other people can easily contribute and expand the existing set. Only one source code has to be maintained. Of course the computational speed is slower than for special purpose programs, but those modules are easy to understand and code is not redundant. I see this as a big improvement compared with my existing code and will help me to show algorithms in manageable, easy to understand pieces.