Abstract: A framework enables data source components to be developed independently of data consumer components. A mediation layer, typically implemented as a group of APIs (application programming interface), handles and defines the mediation and interface between the source and data components. The framework, called XIS (extensible information system), is especially suited for development of information-handling systems and applications. Data source components and data consumer components are typically designed to communicate with each other via several interfaces. Domain, relationship, attribute/metadata, and change event interfaces are defined within the mediation layer. Other interfaces may also be defined. Data source components that are written for non-XIS aware environments or frameworks may still be used with XIS by “wrapping” such source components with code to conform to the interface requirements. Java objects are examples of data source components.