Pligg is an Open Source Web 2.0 CMS. The main features that make
Pligg unique are collaborative bookmarking, social networking,
folksonomy and blogging. Each of the News links, unit of pligg
content, has a vote button, URL and optionally a short description
of news. Here Visitors are supplier, consumer and judge of the
content. Every visitor has right and freedom to vote and veto any
news item. At the end of the day, depending on count of vote news
are either promoted to main site,or move or remains in incoming
queue, or permanently removed from site. Being a collaborative CMS,
Pligg sites grow very fast in terms of traffic and popularity.

WWW: http://www.pligg.com/