1. CYCLADES and SDLIP Simple Digital Library Interface Protocol D-Lib Magazine, March 2000 www.dlib.org

2. SDLIP - Issues State maintenance Complexity management Query language and format neutrality Transport neutrality

3. Search Middleware

4. State maintenance Search in DLs is highly interactive State maintenance with http difficult (stateless protocol) SDLIP: "parking meter" approach

5. Complexity Mgmt, Extensibility Restricted set of features vs. rich core (e.g. Z39.50) SDLIP: Metaobject protocols: Protocol components as objects with own metalevel interface Partitioning of operations into coherent interfaces Extensibility by adding interfaces

6. Partitioning of Operations

7. Query Language and Format Neutrality Query language One basic query language as minimum standard (analogous to DASL) Other query languages can be used as well Format of search results: XML

8. DASL Miller 1994

9. Transport Neutrality

10. SDLIP for CYCLADES Features relevant for CYCLADES: State maintenance Complexity management Transport neutrality Features to be extended: Query language and format neutrality Features to be added: Interface definitions for additional services