Sheep - Membership and events for SMEs and nonprofits
Disciple - Grow, engage and monetise your community with Disciple community software. Get your own branded community platform on Web, iOS and Android
Galette - Galette is a membership management web application towards non profit organizations.
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!
TidyHQ - Organization management tool to support membership, subscriptions, event planning, and outreach.
Proboards - ProBoards is a host of free forums with customer service.