Wikidata
Wikidata (.org) is an effort to store and serve structured data to Wikimedia wikis and to a more limited extent to other parties. Wikidata was started in 2012. The software developed is known as the Wikibase extension.
Wikibase allows interwiki links to be managed with Wikidata removing much contributor annoyanges, redundancy and error-proneness.
Obviously a main source of reference level data.
More info
Useful resources
- mw:Wikidata Toolkit is a way for Java programs to access data in the Wikidata repository.
See also
- Database for a higher level view of what is going on with the databases
- Semantic MediaWiki is system for inputting and querying semantic data within the MediaWiki and it is implemented as extension(s).
- DBpedia the original structured data harvesting effort for the MediaWiki wikis