Citizendium - A wiki for providing free knowledge where authors use their real, verified names.

Miraheze - Miraheze is a wiki farm (hosts wikis) for free and with no ads, it also provides custom domains...

Wikipedia - Wikipedia is a free online encyclopedia, created and edited by volunteers around the world and hosted by the Wikimedia Foundation.

Fandom - The entertainment site where fans come first.

Wikipanion - Wikipanion is the best and fastest Wikipedia browsing application for the iPhone.

Editthis - A free wikifarm project allowing to keep private wiki and build it up through MediaWiki syntax.