Pligg is an open source version of digg: http://pligg.com/ http://pligg.com/ HackerNews runs on ARC Forum: http://arclanguage.org/forum http://arclanguage.org/

Pligg is an open source version of digg: http://pligg.com/ http://pligg.com/ HackerNews runs on ARC Forum: http://arclanguage.org/forum http://arclanguage.org/forum Reddit is open source: https://github.com/reddit/reddit/wiki https://github.com/reddit/reddit/wiki