Wikidata – Free Knowledge Base That Anyone Can Edit
https://www.wikidata.org/wiki/Wikidata:Main_Page

Wikidata is a free knowledge base that can be read and edited by humans and machines alike. It is for data what Wikimedia Commons is for media files: it centralizes access and management of structured data, such as interwiki references and statistical information. Wikidata contains data in all languages for which there are Wikimedia projects. You can read the introduction to learn more about Wikidata. This has been added to Research Resources Subject Tracer™ Information Blog. This has been added to Knowledge Discovery Subject Tracer™.