Ground is an open-source data context service , a system to manage all the information that informs the use of data. Data usage has changed both philosophically and practically in the last decade, creating an opportunity for new data context services to foster further innovation. In this paper we frame the challenges of managing data context with basic ABCs: Applications, Behavior, and Change. We provide motivation and design guidelines, present our initial design of a common metamodel and API, and explore the current state of the storage solutions that could serve the needs of a data context service. Along the way we highlight opportunities for new research and engineering solutions.