This is a list of notable social software: selected examples of social software products and services that facilitate a variety of forms of social human contact.
Blogs
Apache Roller
Blogger
IBM Lotus Connections
Posterous
Telligent Community
Tumblr
Typepad
WordPress
Xanga
Clipping
Diigo
Evernote
Instant messaging
Comparison of instant messaging clients
IBM Lotus Sametime
Live Communications Server 2003
Live Communications Server 2005
Microsoft Lync Server
Internet forums
Comparison of Internet forum software
Internet Relay Chat (IRC) Internet Relay Chat
eLearning
Massively multiplayer online games
Media sharing
blip.tv
Dailymotion
Flickr
Ipernity
Metacafe
Putfile
SmugMug
Tangle
Vimeo
YouTube
Zooomr
IBM Lotus Connections
Media cataloging
Online dating
Web directories
Social bookmarking
Web widgets
AddThis
AddToAny
ShareThis
Social bookmark link generator
Websites
Enterprise software
Altova MetaTeam
IBM Lotus Connections
Jumper 2.0 Enterprise
Social cataloging
aNobii
Goodreads
Knowledge Plaza
Librarything
Readgeek
Shelfari
KartMe
Social citations
BibSonomy
CiteULike
Connotea
Jumper 2.0 Enterprise
Knowledge Plaza
Mendeley
refbase
Zotero
Social evolutionary computation
Knowledge iN
Quora
Yahoo! Answers
Social login
Social networks
Social search
Jumper 2.0
Knowledge Plaza
Social customer support software
Virtual worlds
Active Worlds
Google Lively (now defunct) Kaneva Second Life There Meez