Abstract
A focus of digital libraries, particularly since the advent of the Open Archives Initiative Protocol for Metadata Harvesting, is aggregating from multiple collections metadata describing digital content. However, the quality and interoperability of the metadata often prevents such aggregations from offering much more than very simple search and discovery services. Shareable metadata is metadata which can be understood and used outside of its local environment by aggregators to provide more advanced services. This paper describes shareable metadata, its characteristics, and its importance to digital library development, as well as barriers and challenges to its implementation.