The Institute of Atmospheric Physics of the German Aerospace Center (DLR) uses the numerical model system ECHAM/MESSy Atmospheric Chemistry (EMAC). The model has a flexible modular structure and allows for coupled chemistry-climate simulations. Typical fields of application are related to questions regarding Earth's climate, atmospheric chemical composition, and aerosol characteristics. In its current setup, the performance of EMAC on LRZ/ALTIX allows for multi-decadal simulations with climatologically significant results. The good performance demonstrates the multi-purpose capabilities of LRZ/ALTIX because EMAC involves various different numerical concepts and implementations of parallel decomposition. Our EMAC activities on LRZ/ALTIX are devoted to both model development and production simulations. The former comprise a new upper-boundary representation, a chemistry-transport mode, the inclusion of a mixed-layer ocean, and full-Lagrangian transport and dynamics. The latter tackle, for instance, questions related to the environmental impact of anthropogenic aerosol and gaseous substances.