  In this article, a new generic higher-order finite-element framework for
massively parallel simulations is presented. The modular software architecture
is carefully designed to exploit the resources of modern and future
supercomputers. Combining an unstructured topology with structured grid
refinement facilitates high geometric adaptability and matrix-free multigrid
implementations with excellent performance. Different abstraction levels and
fully distributed data structures additionally ensure high flexibility,
extensibility, and scalability. The software concepts support sophisticated
load balancing and flexibly combining finite element spaces. Example scenarios
with coupled systems of PDEs show the applicability of the concepts to
performing geophysical simulations.
