Core Services in the Architecture of the National Digital Library for   Science Education (NSDL)
  We describe the core components of the architecture for the (NSDL) National Science, Mathematics, Engineering, and Technology Education Digital Library. Over time the NSDL will include heterogeneous users, content, and services. To accommodate this, a design for a technical and organization infrastructure has been formulated based on the notion of a spectrum of interoperability. This paper describes the first phase of the interoperability infrastructure including the metadata repository, search and discovery services, rights management services, and user interface portal facilities. 
Carl Lagoze, William Arms, Stoney Gan, Diane Hillmann, Christopher   Ingram, Dean Krafft, Richard Marisa, Jon Phipps, John S...