DUNE (Distributed and Unified Numerics Environment) is a modular C++ library for the solution of partial differential equations using grid-based methods. The DUNE library is divided into modules. In version 2.7 are the core modules * general classes and infrastructure: dune-common, * geometry classes: dune-geometry, * grid interface: dune-grid, * linear algebra classes: dune-istl, * local ansatz functions: dune-localfunctions, and a documentation module available. In addition there are several further modules, including some which have been developed by third parties.