Wikitrivia by Tom J. Watson is a game you can play for free in your browser. You get cards representing historical events, and have to put them in chronological order (like the card game Chronology). The software reuses data from the Wikimedia project Wikidata (previously).

Watson notes: “There are some cards that unfortunately don’t quite make sense or have bad data. These need to be removed from the game and, ideally, to have their underlying wikidata entry fixed. Please report any bad cards here.”