EspoCRM - EspoCRM is open source CRM (Customer Relationship Management) software that allows you to see, enter and evaluate all your company relationships regardless of the type.
TelephoneLists.Biz - Telephonelists.biz is the source for phone leads for sale, provides the agents with a wide audience full of leads ready to become the next customers.
CiviCRM - A Constituent relationship management for the Civic Sector
LeadGibbon - Access millions of business contacts, with verified email addresses and phone numbers
Less Annoying CRM - A simple customer relationship manager made just for small businesses. Manage contact info, track leads, and never miss a follow-up.
ZoomInfo - ZoomInfo is a B2B database providing detailed business information on people and companies.