AbstractIn this paper we describe the basic services and architecture of Gateway, a commodity‐based Web portal that provides secure remote access to unclassified Department of Defense computational resources. The portal consists of a dynamically generated, browser‐based user interface supplemented by client applications and a distributed middle tier, WebFlow. WebFlow provides a coarse‐grained approach to accessing both stand‐alone and Grid‐enabled back‐end computing resources. We describe in detail the implementation of basic portal features such as job submission, file transfer, and job monitoring and discuss how the portal addresses security requirements of the deployment centers. Finally, we outline future plans, including integration of Gateway with Department of Defense testbed Grids. Copyright © 2002 John Wiley & Sons, Ltd.