Community Systems: The World Online
             Raghu Ramakrishnan, Yahoo! Research

The Web is about you and me. Until now, for the most part, it has
denoted a corpus of information that we put online sometime in the
past, and the most celebrated Web application is keyword search over
this corpus. Sites such as del.icio.us, flickr, MySpace, Slashdot,
Wikipedia, Yahoo! Answers, and YouTube, which are driven by
user-generated content, are forcing us to rethink the Web--it is no
longer just a static repository of content; it is a medium that
connects us to each other. What are the ramifications of this
fundamental shift? What are the new challenges in supporting and
amplifying this shift?