The Retsina Semantic Web Calendar Agent, RCAL, supports the browsing and tasking of information and services on the Semantic Web, and integration with MS Otlook. Schedules and agendas, that may be fragmented across the web, with references to speakers and locations defined in DAML and RDF are combined to display coherent schedules that can then be imported. In addition, each of the concepts displayed can be used to locate and invoke related services, through the use of discovery services.
RCal may be invoked from the Start Menu or from the icon that is placed on the desktop. On invocation, the agent contacts the local implementation of Outlook to load the user's agenda and contact list. This information is used for distributed meeting scheduling. Once loaded, the Current Events Browser will appear on the screen, and the RCal Agent icon will appear in the system tray. This system tray icon can be used to retrieve the Current Events Browser (when iconified), and to access other browsers, such as the Semantic Web Browser.
The agent utilises much of Outlook's Calendar functionality, without the need for running Outlook. When executing, many of the Outlook modules are loaded and accessed by the agent. Thus the agent can utilise many of Outlooks services, such as notifications and reminders, and the ability to post mail and set personal appointments.
The first time the agent starts, agent registration information is requested by the agent (see opposite). Agent registration is not necessary to use the agent, however, functionality is limited as without retinstration, requests to other agents cannot be conducted. For example, registration is not necessary for browsing Semantic Web Agendas that use the ICal ontology; however, translation services and distributed meeting scheduling cannot be conducted without contacting these services (which involves contacting Agent Registry.
Registering the agent simply involves providing a unique name to the agent and registering this with an Agent Name Service (one is provided at www.daml.ri.cmu.edu on port 6677). RCal uses an email based scheme for naming agents - users can construct the Agent name by appending "-CalendarAgent" to their email address (note that the '@' character should be replaced by '_'). This construction is performed automatically by typing the email address in the email address form within the ANS Registration; as the address is entered, the constructed agent name appears below.
The user can display or hide the Current Events Browser by double clicking the system tray icon. However, if the user right-clicks this icon, then a menu appears with the following choices: