The chart engine API uses the Eclipse Modeling Framework (EMF) as a structured data model. Use the classes and interfaces in the chart engine API to modify chart objects within a BIRT reporting application or in a stand-alone charting application.

The Chart Engine API includes many packages in the org.eclipse.birt.chart hierarchy. The model.* packages contain the core chart model interfaces and enumeration classes generated using EMF. The model.*.impl packages contain the core chart model implementation classes generated using EMF. All other packages are dependencies from and indirect references to the core model. There is a one-to-one correspondence between classes in the impl packages and interfaces in matching model packages. The classes in the impl packages implement the methods in the interfaces of the model classes. The impl classes also contain factory methods used to create an instance of a class.