Recommended by many users and won awards, Elgg is one of the most powerful tools out there for building complex social networks.
Here are some key features of "Elgg":
· User profiles
· Full RSS support
· RSS aggregator
· Create communities
· Collaborative community blogs
· Create 'friends' networks
· Import content
· Publish to blog
· OpenID support
· Social networking
· File repositories for individuals and communities
· Podcast support
· Full access controls
· Supports tagging
· mod_rewrite activated in Apache
· JSON library
· GD library
· Multibyte String support
· PHP 5.2 or higher
· MySQL 5 or higher
What's New in This Release: [ read full changelog ]
· Fixed the "http://" issue for profiles
· Added a helpful message for those sites that have a configuration error related to multiple URLs mapping to the same site. This was also exposed by fixing a bug in 1.8.14.
· Restoring sub-pages that have been missing after their parent page was deleted (pages plugin).
· Better revision support for pages (pages plugin).
· Adding nofollow to auto linked URLs to discourage spammers (thanks to Hellekin Wolf for pointing that out)
· Added browser caching for languages JS files