Using DD4hep through Gaudi for new experiments and LHCb

The LHCb Software Framework Gaudi is a C++ software framework for HEP applications used by several experiments.Although Gaudi is extremely flexible and extensible, its adoption is limited by the lack of certain components that are fundamental for the software framework of an experiment, in particular a detector description framework, whose implementation is delegated to the adopters.To enable future experiments to quickly adopt Gaudi, we integrated the DD4hep toolkit in the existing software framework, and, as a proof of concept, we used it with the LHCb software applications, from simulation to reconstruction and analysis.We will describe how the DD4hep toolkit can be used by a new experiment, as well as how we can migrate an existing detector description framework to the new toolkit.