Wikimedia Foundation
Empowering the sum of all human knowledge through collaborative projects and advocating for free knowledge. Discover how you can #ChangeTheStats with Wikipedia.
wikimediafoundation.org · 71,272
Stack Exchange
Community-powered Q&A site with over 170+ communities on various topics.
stackexchange.com · 25,670
PubPub
Community publishing platform for creating and sharing knowledge with a focus on collaboration and open access.
pubpub.org · 9,176
