A shared, common event data model, EDM4hep, is an integral part of the Key4hep
project. EDM4hep aims to be usable by all future collider projects, despite
their different collision environments and the different detector technologies
that are under discussion. This constitutes a major challenge that EDM4hep
addresses by using podio, a C++ toolkit for the creation and handling of event
data models, developed in the context of the AIDA R&D program. This approach
allows for quick prototyping of new data types and provides a streamlined
framework for updates. After presenting an overview of the basic features of
EDM4hep and podio, we will discuss the current experience with an initial
version of EDM4hep in different physics studies. Additionally, we will present
the planned developments that are necessary for a first stable version of
EDM4hep, addressing in particular backward compatibility aspects and schema
evolution. We will conclude with an outlook on the future developments
directions beyond this first stable version.