An application integration system used to integrate a plurality of applications includes a plurality of integration adapters, each communicating with an application and an integration engine including a messaging broker, an integration database and a schema mapping. database. The application integration system also uses a plurality of tools and components interactively working with the messaging broker. The application integration system allows integrating various applications and at the same time provides ease of change to users of such applications by providing a framework that may be used to customize and configure integrations leading to significant reduction in total cost of ownership to the businesses.