  We present our effort to extend and complement the core modules of the
Distributed and Unified Numerics Environment DUNE (http://dune-project.org) by
a well tested and structured collection of utilities and concepts. We describe
key elements of our four modules dune-xt-common, dune-xt-grid, dune-xt-la and
dune-xt-functions, which aim at further enabling the programming of generic
algorithms within DUNE as well as adding an extra layer of usability and
convenience.
