Oppia is a free, open-source learning platform. Full of interactive activities called 'explorations', Oppia helps curious minds learn and teach.
Platforms
- Mac
- Windows
- Linux
- Online
- Self-Hosted
United States

Wikiless has been discontinued. Similar apps include Wikipedia, which is free and open source. Other options are Kiwix, Grokipedia, WikiReader and Encyclopædia Britannica. Encyclopedias like Wikiless are a crowded field, with more than 50 alternatives for the web, Android, iPad, iPhone and Linux.
Oppia is a free, open-source learning platform. Full of interactive activities called 'explorations', Oppia helps curious minds learn and teach.

Non-profit history encyclopedia with the mission to engage people with cultural heritage and to improve history education worldwide.



HandWiki is a wiki encyclopedia dedicated to scientific computing and science. This wiki can be used for collaborative editing of articles about applications of computers and software programs in different areas of science, finance and engineering.

IFWiki is a wiki containing information about interactive fiction, including IF history, theory, craft, tools, and people. IFWiki serves as both a historical record of community knowledge and a guide to resources for playing and creating interactive fiction.


Community-driven catalog of learning resources. Links to resources are organized by topics and rated/reviewed by users so you see which ones are the best. It's free and open for everyone.




LibreGameWiki the free gaming encyclopedia for games developed as open source and using open media.



Online dictionary and encyclopedia with pictures, facts, and videos. Get information and homework help with millions of articles in our free, online library.
WikiPathways was established to facilitate the contribution and maintenance of pathway information by the biology community. WikiPathways is an open, collaborative platform dedicated to the curation of biological pathways.

User-editable encyclopedia for fans of anthropomorphic animals. Over 18,000 articles on furry community and culture in twenty-one languages.
Worldometers is run by an international team of developers, researchers, and volunteers with the goal of making world statistics available in a thought-provoking and time relevant format to a wide audience around the world.