Heron components and data utility classes extend map related functionality to equivalent classes in GeoExt and ExtJS. The API reference here documents the properties, methods, and events that are extensions or modifications to the GeoExt and Ext parent classes. Documentation for each class contains links to the parent class, and for a full picture of the API, it is essential to have a links to the ExtJS API Documentation , GeoExt API Documentation and OpenLayers API Documentation at hand.
NOTE: the Heron API docs are work in progress!