The best open source alternative to Wikipanion is Citizendium. If that doesn't work for you, our users have ranked more than 10 alternatives to Wikipanion, but unfortunately only two of them is open source. If you can't find an alternative you can try to remove all filters.
Citizendium, powered by MediaWiki, is "an open wiki project dedicated to creating a free, comprehensive, and reliable repository of structured knowledge". Unlike with Wikipedia, a contributor must register using their real name and verify their identity.
