Vtiger
Vtiger is an open source CRM with an all-in-one sales, marketing and service product, plus individual modules for customers who want to start out with just one of the three. With both cloud and open source, self hosted options; Vtiger recommends using the cloud for security, zero maintenance, better performance and a low per user cost. Add-ons from Vtiger allow users to synchronize with Microsoft Exchange and Asterisk servers, while third-party add-ons include notepads, online payment processing and more. On boarding kickstart programs for customers that want to get the most out of their Vtiger deployment are offered as well. Vtiger's free apps for iPhone, iPad, and Android users allow for a mobile workforce that has all the information they need at their fingertips. Available in over 20 languages, the open source CRM is used by customers in over 110 countries.