Structural Metadata and the Social Limitation of Interoperability: A Sociotechnical View of XML and Digital Library Standards Development
(source: Balisage: The Markup Conference, août 08)

"Ten years after its endorsement by the World Wide Web Consortium, XML has achieved a high degree of adoption within numerous, disparate communities and in a vast range of application domains, from standards for electronic filing of federal income tax (Internal Revenue Service, 2007) to user interface design (Goodger et al., 2001). The digital library community has been an active and early adopter of XML, for use in structuring both content and metadata. The reasons for this rapid uptake of XML within the digital library community are familiar to anyone with experience in the world of markup languages:
- XML helps ensure platform (and perhaps more critically vendor) independence;
- XML provides the multilingual character support critical to the handling of library materials;
- XML's extensibility and modularity allow libraries to customize its application within their own operating environments;
- XML helps minimize software development costs by allowing libraries to leverage existing, open source development tools;
- XML, through virtue of being an open standard which enables descriptive markup, may assist in the long-term preservation of electronic materials; and perhaps most importantly
- XML provides a technological basis for interoperability of both content and metadata across library systems.
For all of these reasons, XML-based content standards such as the Text Encoding Initiative (TEI) have seen wide adoption within the library community, and librarians have been actively engaged in the development of a number of XML-based metadata standards, including Encoded Archival Description (EAD), Metadata Object Description Schema (MODS), Metadata Authority Description Schema (MADS), Metadata Encoding and Transmission Standard (METS), Metadata for Images in XML (MIX), MPEG-21 Digital Item Declaration Language (DIDL), Open Archives Initiative Object Reuse and Exchange (OAI-ORE), Preservation Metadata Implementation Strategies (PREMIS) and many others. XML is now widely used throughout the research library world, and is a fundamental part of the infrastructure developed within the digital library community over the past decade."