The SDR uses Hydra, a complete solution composed of open source technologies, including:
- Fedora - serving as a robust, durable repository for managing digital objects. Fedora's design lends itself well to establishing flexible relationships with other components of the digital library, accommodating inevitable changes to the repository structure over time.
- Solr - used to index information and offers "blazing fast" search of the repository contents. Solr's flexibility can accommodate a diversity of data sources.
- Blacklight - builds on the Solr index to provide faceted searching, browsing and tailored views of objects.
In combination with these technologies, Stanford Libraries developed Moab for versioning archived digital objects. Details about this novel approach are available in this 2013 article originally published in the Code4Lib Journal.
In addition to the access copies readily available online, one preservation copy of SDR content is stored on spinning disk and multiple copies are stored on LTO tape. The tapes are stored in geo-diverse locations.
For more information about the SDR's underlying technology, please contact the SDR team.