The design of the user interface is a crucial element for the success of the Alexandria Project. The users of Alexandria will require simple and naturally expressive methods for accessing and retrieving spatial and non-spatial information. The functionality of the interface component involves support for text-based and visually-based query languages that permit a user to express, in simple terms, queries concerning the existence, characteristics (including content), and availability of datasets that satisfy various constraints. It will permit users to browse datasets that are candidates to satisfy the constraints expressed in their queries and to request selected datasets transmitted to locations of their choice. The interface will be responsible for determining how the complete processing of a query should be partitioned between the client site and the server site.