The IBM Watson Dialog service provides a comprehensive, technology platform for managing conversations between virtual agents and users through an Application Programming Interface (API).
The Dialog service enables your applications to use natural language to automatically respond to user questions, cross-sell and upsell, walk users through processes or applications, or even hand-hold users through difficult tasks. The Dialog service can track and store user profile information to learn more about end users, guide them through processes based on their unique situation, or pass their information to a back-end system to help them take action and get the help they need.
More information: http://www.ibm.com/smarterplanet/us/en/ibmwatson/developercloud/dialog.html