Hive Index - Discover online communities, across all platforms, for any topic.
Disciple - Grow, engage and monetise your community with Disciple community software. Get your own branded community platform on Web, iOS and Android
Community Canvas - A framework to build meaningful communities
Forumotion.com - Create a free forum : free forum hosting, free forum skins, templates editing, chatbox, RPG mod... Choose PhpBB 2 - 3, Invision or PunBB. Create forums now!
Butter - Butter is a newly launched chatting application that focuses more on the privacy of its users.
Proboards - ProBoards is a host of free forums with customer service.