Membership management software. From their website (http://www.wildapricot.com/): "Build, connect & grow your association, non-profit, or club.
• Say goodbye to Excel and paper records
• Membership software "in the cloud"
• Volunteers can use it from any browser, nothing to install
• Manage member sign-up, renewals and payments
• Promote and manage event registrations online
• Build your public and members-only website".