Status.net

Free and Open Source social microbloging software similar to twitter. User have option to post status/microblog which is not limited to 140 characters like on twitter. Users can also create groups with unique name, addresse and dedicate page that holds group description and activity posted to group. If user wont to assign post to group, he doesn't have to go to group page, he just need to add unique group name with exclamation mark in this format !groupname. Groups are similar to tags, in user post !groupname become a clickable link to group. Status.net also support decentralization, you could install your own instance and communicate with other status.net users on the web. Status.net was developed by Evan Prodromou to power identi.ca microbloging website. Evan later created new software called pump.io which now runs on identi.ca and stopped support for status.net. Development of status.net is moved to GNUSocial.