HubSpot CRM - Free CRM software for small businesses.
Kajabi - Kajabi is the only Knowledge Commerce platform today with everything you need to market, sell, and deliver your knowledge online.
Less Annoying CRM - A simple customer relationship manager made just for small businesses. Manage contact info, track leads, and never miss a follow-up.
Tendenci - Tendenci - The Open Source AMS is a cloud-based all-in-one management SaaS solution for Non-profits and Associations.
Keap - Grow Sales. Save Time. Get Organized.
YourMembership - YourMembership provides membership management software integrated with social networking features.