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

Encyclopædia Britannica - Explore the fact-checked online encyclopedia from Encyclopaedia Britannica with hundreds of thousands of objective articles, biographies, videos, and images from experts.

WikiSpooks.com - WikiSpooks is a global alternative encyclopedia on politics, spy craft, deep state intelligence, and conspiracies, free of corporate influence, partisan politics, or government propaganda for historians and truth-seekers to read, edit, and share.

Investopedia - Investopedia has a lot of information to share with business mind people.

Oppia - Oppia is a free, open-source learning platform.

WikiGenes - The world's first wiki where authorship really matters. Imagine a global collaborative knowledge base for original thoughts. Open access and freely available to everyone.