DigitalPreservationEurope has published a new briefing paper: Interoperability: A Key Concept for Large Scale, Persistent Digital Libraries.
Here's an excerpt:
Interoperability is an essential feature for federated information architectures to work in heterogeneous settings and over time! However, use and understanding of the concept still are very heterogeneous: interoperability is conceived in an object-related or in a functional perspective, from a user's or an institutional perspective, in terms of multilingualism or of technical means and protocols. Moreover, interoperability is conceived on different abstraction levels: from the bitstream layer up to semantic interoperability. The briefing summarises some of the relevant vectors of thought, indicates related conceptual frameworks and places the issue in the strategic context of Europeana.
The link to the paper should be:
http://www.digitalpreservationeurope.eu/publications/briefs/interoperability.pdf