Wikipedia - Wikipedia is a free online encyclopedia, created and edited by volunteers around the world and hosted by the Wikimedia Foundation.
Lunyr - A decentralized crowdsourced encyclopedia.
Kiwix - Kiwix enables you to have the whole Wikipedia at hand wherever you go!
Curius - Save links and highlights to a beautiful personal page
Oppia - Oppia is a free, open-source learning platform.
Tealfeed - A knowledge sharing platform to empower creators