Feed Aggregator Reader (branched from FeedOnFeeds) with Social Bookmarks (del.icio.us, Blogger, Newsvine, Technorati, mailto), Article Starring, Feed Tagging, OPML, Article Search, Reblogging and Refeeding, Aging, and Edit feed attributes. PHP and mySQL
http://slashdot.org/article.pl?sid=04/03/30/2333258
"When Orkut, LinkedIn, Friendster, Zaibatsu and Tribe.net just don't cut it, meet PeopleAggregator, an open-source, PHP-written, FOAF-based social network. There's the site and there's the source in case you decide to launch your own. I found out about PeopleAggregator reading this interview with Mark Canter on Read/Write Web today."