Wikipedia
Wikimedia
Other wikis:
- Wikimedia Foundation: MediaWiki (Wiki software) | Bugzilla (MediaWiki development) | Wikia (Wikia)
- Specialized Wikis: StrategyWiki (Game guides) | Halopedia (Halo) | Memory Alpha (Star Trek)
- MetaWiki: TVTropes.org
- More Wikis: No matter what the topic, there's a wiki for that