Pligg is an open source Content Management System (CMS) that allows you to create a site where registered members can submit, publish and rank articles based on the quality of content. Since Pligg is based on open source PHP and MySQL technologies you can install it on most web hosts on a relatively small budget.
Pligg uses the Smarty template system to keep code separate from the design. This makes updating your site to the latest version of Pligg easier, and designing new templates a breeze. Pligg’s architecture is modular and you you can extend it’s functionality without having to alter main code. There is already a large library of modules (both free and commercial) to choose from that will greatly enhance your Pligg site.
Pligg code is published under the Affero General Public License (AGPL), which is a modified version of the GNU General Public License (GPL). You an find further information, download and demo on Pligg’s Website.