Pligg is an open source content management system available for download at no cost. Pligg is based on PHP/MySQL.

he 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.