postActiv is a free software project to develop a social networking platform. It is derived from GNU Social, which is itself derived from StatusNet and Laconica. It helps people in a community, company, or group to exchange short status updates, do polls, announce events, or other social activities. Users can choose which people to "follow" and receive only their friends' or colleagues' status messages. They can also view the public timeline of the site to see everyone, or the "whole known network" timeline, to see all the people in sites that have connected with this one, by someone following them. It provides a similar service to proprietary social network sites, but is decentralized, and with many additional features and an open, free software codebase that you can develop your own plugins for, it is much more awesome.