Authors: Andra Waagmeester, Katherine Thornton and @addshore Wikidata is the linked database maintained by the Wikimedia Foundation, which also maintains Wikipedia. As an online encyclopedia, Wikipedia is one of the most visited websites worldwide. Started in 2001 as an English website it currently has versions in more than 290 languages and is still growing. All these (connected) Wikipedias are running on a software platform called Mediawiki. This Mediawiki stack has been released as open software to general public and has since been used in many, many cases outside the Wikimedia ecosystem.