Matt Jones defines it as software that's better because there's people there.
or software that gets better as more people use it
Clay Shirky comments on that page uses Social software treats triads of people differently than pairs and Social software treats groups as first-class objects in the system
Nov'2002: Clay Shirky-organized Social Software Summit: 2002-12-09-ClayShirkySocialSoftware
Stewart Butterfield Mar'2003 definition/dimensions - Identity; Presence; Relationships; Conversations; Groups
- Matt Webb adds Reputation and Sharing, and discusses those 7 dimensions in terms of AIM.
Includes tools for (at least) both Virtual Community and Collaboration Ware.
Dion Hincliffe Apr'2008 checklist
see Social Software Alliance (2003)