• Usenet, one of the original decentralized, distributed discussion group architectures.
• BBS: The WELL, GEnie, The Meta Network
• Academic: EIES, Usenet
• Blog: LiveJournal, Xanga, MySpace, Facebook, WordPress, Blogger, TheStudentRoom, Tagged, Twitter
• Webcomic: UserFriendly, Penny Arcade, Sluggy Freelance
• Virtual world/city: LucasFilm's Habitat, Second Life, Millsberry, Red Light Center, IMVU, Neopets, Roblox
• IM: ICQ, Yahoo! Messenger, Windows Live Messenger, AIM, Facebook Messenger, WhatsApp, Kik Messenger, WeChat, Viber, Discord, Skype, iMessage, KakaoTalk, Line, Telegram
• Internet Relay Chat (IRC): IRC networks
• MMORPG: EverQuest, Final Fantasy XI, RuneScape, World of Warcraft, Final Fantasy XIV, Star Wars: The Old Republic
• MOO: LambdaMOO
• Mososo: Dodgeball, Meetro, Foursquare
• MUD/MUSH: TinyMUD
• P2P: Kazaa, Morpheus, Napster, Limewire, BitTorrent
• Wiki: Wikipedia, WikiWikiWeb, MeatballWiki, Wetpaint, PBworks, TV Tropes
• WWW: eBay, Slashdot, Digg, Reddit
• Consumers: eBay, Amazon.com
• Software that enable online communities: Ning

Discussion boards edit

• reddit
• Hacker News
• Dead Runners Society
• 4chan
• GameFAQs
• Something Awful
• Fark
• 2channel
• Zombie Squad
• IGN
• TOTSE

Social networking edit

Art communities edit

• Albino Blacksheep
• DeviantArt
• Dulwich OnView
• Elfwood
• Newgrounds
• Tumblr

MUD, MUSH, MOO edit

• Category:MUD games
• Category:MU* games

Virtual world communities edit

• Category:Virtual world communities

Virtual reality communities edit

• Category:Virtual reality communities

Ethnicity-based communities edit

• 1Point3Acres
• Fillos de Galicia
• MIT BBS

Online Teaching Covens edit

• Coven of the Far Flung Net

Other types edit

• Pinboard
• bianca.com
• Scratch (an educational programming website by MIT)
• GameTZ.com (an online game, music, movie, and book trading community)
• CouchSurfing (free accommodation worldwide through hospitality exchange)
• Hospitality Club (free accommodation worldwide through hospitality exchange)
• Warm Showers (free accommodation worldwide through hospitality exchange for bicycle travelers)
• Meetup (an online service designed to facilitate real-world meetings of people involved in various virtual communities)
• Meetro (local focused communities)
• StumbleUpon (web surfing)
• Woozworld (virtual gaming community for youth)
• YTMND (Picture, Sound, Text)
• Group blogs
• TakingITGlobal (Youth - social networking for social good)
• CrossFit (a fitness program where users post their scores and comments on daily workouts)
• DXY.cn (an online community for physicians, health care professionals, pharmacies and facilities)

• List of virtual communities with more than 1 million users
• List of social bookmarking websites
• List of social networking websites
• List of Internet forums
• Lists of websites
• Support group