TidyHQ - Organization management tool to support membership, subscriptions, event planning, and outreach.

Admidio - Admidio is a free online membership management, which is optimized for associations, groups and organizations.

Galette - Galette is a membership management web application towards non profit organizations.

Google Groups - Google Groups allows you to create and participate in online forums and email-based groups with a rich experience for community conversations.

Mighty Networks - Mighty Networks enables entrepreneurs, organizations, and companies to create and grow a community-powered brand.

Membee - Membee is web-based membership management software.