Wikipedia - Wikipedia is a free online encyclopedia, created and edited by volunteers around the world and hosted by the Wikimedia Foundation.
MediaWiki - MediaWiki is a free software wiki package written in PHP, originally for use on Wikipedia.
Encyclopædia Britannica - Explore the fact-checked online encyclopedia from Encyclopaedia Britannica with hundreds of thousands of objective articles, biographies, videos, and images from experts.
TiddlyWiki - a non-linear personal web notebook
Kiwix - Kiwix enables you to have the whole Wikipedia at hand wherever you go!
Confluence - Confluence is content collaboration software that changes how modern teams work