Virtual information systems are made possible by the advent of gateway or front-end software, which allows a user to access multiple computer systems via a single terminal and single log-on. Such virtual systems bring together more extensive selection of on-line services than could be comfortably accessed previously. Equally important as the improved breadth and ease of access is the powerful information analysis and processing capability which these systems provide. A general review of the current status of virtual information systems is followed by a description of a prototype system developed by Lawrence Livermore National Laboratory.