Vtiger CRM is an open source CRM application that was forked from SugarCRM with the intention of being a fully open source CRM application with comparable functionality to SugarCRM and Salesforce.com. It offers reporting, a customer portal and an Outlook plugin in its free edition, whereas those functions are in paid versions of the other CRM applications.
In addition, vtiger features multiple database support, security management, and various web forms. The project is available in over 15 different languages.
Interface similarities between vtiger and the CRM module of the Zoho Office Suite have been noted. However, this seems to be attributable to common corporate sponsorship, not to a common software code base.
Vtiger is built on the LAMP/WAMP (Linux/Windows, Apache, MySQL, and PHP) stack with code from other open source projects such as SugarCRM. The core development team of vtiger CRM is based in Bangalore, India.
Vtiger CRM installation is done entirely from an HTML/PHP web interface. One can install vtiger CRM 4.X and 5.x on a standard webserver from cpanel provided they have the correct version of PHP and mySQL already installed. From 5.x, the package comes bundled with PHP/MySQL installations, fully customizable.