Wikipedia
wikipedia.org ↗The free, volunteer-written encyclopedia in hundreds of languages.
For everyone; it's often the first stop for a fact, and you can fix what's wrong.
Why it’s listed
Hosted by the Wikimedia Foundation, 'the non-profit organization behind Wikipedia', and written by nearly 250,000 volunteers, free and 'without advertising or paywalls'1.
The trade-off
It relies on yearly donation appeals, and any article can be edited, so check the sources it cites.
Price
Free.
