Class List
Here are the classes, structs, unions and interfaces with brief descriptions:

Atk::Action | The ATK interface provided by UI components which the user can activate/interact with, This should be implemented by instances of Atk::Object classes with which the user can interact directly, i.e
Atk::Component | The ATK interface provided by UI components which occupy a physical area on the screen
Atk::Document | The ATK interface which allows access to a DOM associated with on object
Atk::Hyperlink | Encapsulates a link or set of links in a hypertext document
Atk::Image | The ATK Interface implemented by components which expose image or pixmap content on-screen
Atk::NoOpObject | An Atk::NoOpObject is an Atk::Object which purports to implement all ATK interfaces
Atk::Object | The base object class for the Accessibility Toolkit API
Atk::ObjectAccessible | This object class is derived from AtkObject and can be used as a basis implementing accessible objects
Atk::Relation | An Atk::Relation describes a relation between an object and one or more other objects
Atk::RelationSet | A set of Atk::Relations, normally the set of AtkRelations which an Atk::Object has
Atk::Selection | The ATK interface implemented by container objects whose Atk::Object children can be selected
Atk::StateSet | An AtkStateSet determines a component's state set
Atk::StreamableContent | The ATK interface which provides access to streamable content
Atk::Table | The ATK interface implemented for UI components which contain tabular or row/column information
Atk::Text | The ATK interface implemented by components with text content
Atk::Value | The ATK interface implemented by valuators and components which display or select a value from a bounded range of values