Responsible for managing
session state objects, objects which persist between requests, but are not tied to any individual page or component. SSOs are also created on demand. SSOs are typically stored in the session, so that they are specific to a particular client.
The term "Application" is a hold-over from Tapestry 5.0, which used the @ApplicationState (deprecated and deleted) annotation, and called them "ASOs" (Application State Objects). This service would be better named "SessionStateManager" (but renaming it would cause backwards compatibility issues).
Tapestry has a built-in default strategy for storing SSOs (in the session) and instantiating them. If desired, contributions to the service configuration can override the default behavior, either specifying an alternate storage strategy, or an alternate {@linkplain org.apache.tapestry5.services.ApplicationStateCreator creation strategy}.
@see org.apache.tapestry5.annotations.SessionState