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Crowded Communities - The all-in-one community platform.
NationBuilder - The world's first platform for leaders, handcrafted from scratch to help you grow your community and lead them to action.
Discourse - Discourse is an open source discussion platform built for the next decade of the Internet.
Ning - Ning is the social platform for the worlds interests and passions online.
FUEL CYCLE by Passenger - Think Passenger builds online platforms that allow brands to connect, create and communicate with key stakeholders.