A good overview is given in this paper:
Flemisch, B., Darcis, M., Erbertseder, K., Faigle, B., Lauser,
A., Mosthaf, K., Müthing, S., Nuske, P., Tatomir, A., Wolff, M. and R. Helmig,
DuMux: DUNE for Multi-{Phase, Component, Scale, Physics, ...} Flow
and Transport in Porous Media.
Advances in Water Resources 34(9), 2011, 1102-1112.
Some more detailed information can be obtained by scanning through the handbook:
DuMux handbook (Release 2.0).
There also exists an outdated proceedings paper:
Flemisch, B., Fritz, J., Helmig, R., Niessner, J. and B.I. Wohlmuth,
DuMux: A multi-scale multi-physics toolbox
for flow and transport processes in porous media.
In: Ibrahimbegovic, A. and Dias, F. (eds.): ECCOMAS Thematic Conference on Multi-scale
Computational Methods for Solids and Fluids (28. - 30. November 2007, Paris, France). 2007, 82-87.