In Fig. 1, we illustrate the four main components of the architecture for the WP. This architecture is derived from the general architecture of ADL by specifying the languages and protocols at the interfaces between components. A few important aspects of this architecture include: 1) in the storage component, the use of ``handles'' and Internet protocols for transfer; 2) in the catalog component, an extensible metadata model and SQL/Z39.50 query engines; 3) in the interface component, the use of HTTP/HTML, browsers, and external viewers for ``vector'' data; 4) for the ingest component, the creation of catalog entries. Unlike the RP version of ADL, the storage and catalog components are distributed.
Figure 1: The main components of the WP.