Invision Community - Invision Community is a flexible, integrated set of apps for building communities on the web.
Mighty Networks - Mighty Networks enables entrepreneurs, organizations, and companies to create and grow a community-powered brand.
XenForo - Intuitive. Social. Engaging. Fast. XenForo brings a fresh outlook to forum software.
Bigtent - BigTent is a web-based organization and communication portal for groups.
Mobilize - Mobilize is a scalable messaging app built for large groups.
Nabble - Nabble is a forum software that are embeddable and fully customizable with scripting language.