Fat Free CRM

Fat Free CRM is an open source Ruby on Rails-based customer relationship management platform, that focuses on simplicity of use. Out of the box it features group collaboration, campaign and lead management, contact lists, and opportunity tracking.
Fat Free CRM lets small businesses organize and maintain information on all of their customer relations. It provides management of corporate information such as customer contacts, customer accounts, sales leads, and sales opportunities. It also manages activities such as meetings, employee tasks, phone calls, and followups.
Fat Free CRM’s claim to fame is its simple-to-use and intuitive user interface, so technophobes need not fear.