Community Systems: The World Online

Online communities are a fundamental and increasingly important part of the Web. Sites such as Y! Answers, flickr, MySpace, and YouTube are well-known examples. Further, online applications in diverse domains increasingly incorporate community tools, and the richness of the baseline community offerings is growing rapidly. We routinely see bulletin boards with presence and realtime chat, rating and reputation systems, and other such capabilities on a wide range of sites. Today, it is possible to integrate modules providing rich community features using a local database instance. Increasingly, hosted application providers will make such capabilities available, with potential advantages such as single authentication, integrated payment systems, and shared personalization.