1. Elgg - (demo) New to Elgg 1.5 is a comprehensive activity stream which provides an at-a-glance look at activity from across the site, as well as your friends’ activity and your own actions.

You can filter the activity stream to only include particular tools or types of action, making this a powerful addition to your social network.

Optionally, your activity stream can be the first port of call for users logging into the site - or you can use it alongside Elgg’s widget-based dashboard. Users will be presented with the site’s newest members and can post directly to the wire.

2. Dolphin -(demo) Latest Version - 6.1.6 -  YouTube, MySpace, Odeo, Flickr, Match and Facebook - all in one, customizable and under your full control. You’re limited only by your imagination - not by the software. Dolphin Smart Community Builder is a universal, free, open source software that allows you to build any kind of online community. With a huge variety of features & options, you can quickly launch your own very unique and successful website.

Pligg is an open source Content Management System (CMS) that you can download and use for free. Pligg CMS provides social networking software that encourages visitors to register on your website so that they can submit content and connect with other users. Our software creates websites where stories are created and voted on by members, not website editors. Use Pligg content management system to start your own social networking community in minutes.  Demo