Connect. Share. Collaborate.
Elgg is free and open source software
It provides the components you need to build a fully-featured social environment, including:
* Profiles
Elgg comes with default profile fields that can be extended or completely customized by the site administrator.
* Activity Streams
The granular activity stream feature ensures you keep up to date with all site activity.
* Blogging / Microblogging
Blogging and microblogging functionality that is both powerful, yet simple to use.
* Groups
Collaborate around specific topics via public, private or hidden groups.
* Access controls
Control who can access your content.
* Web Services API
Expose functionality through the REST API by building a plugin and then either publish the API for other developers to build clients or provide your own.
* See more features
Using RhNav - Rhizome Navigation I wrote a data aggregator for Technorati's API. The first result is a video which visualizes blog domains by analysing Technorati's Cosmos (the blogs which link to a particular URL). The video is a screencast of RhNav fetc