WikiTimelines is described as 'Wikitimelines is a collection of timelines on people, events and topics that anyone can add to or edit'. There are four alternatives to WikiTimelines, not only websites but also apps for Mac, Chrome OS and Windows. The best alternative is Aeon Timeline. It's not free, so if you're looking for a free alternative, you could try Newslines or Tiki-Toki.
Tiki-Toki is online and desktop timeline maker software for creating beautiful interactive timelines that you can share on the web. Note: free account is limited to one timeline, 200 entries, 50 categories and 5 timeline spans. Why use Tiki-Toki?