The NASA Spatial Web Portal (SWP) is designed to support the open discovery, access, and visualization of geospatial resources. In this paper, we introduce the development of a client for the SWP using Microsoft Bing Maps AJAX APIs. The client consists of three key components: resource search, resource access, and resource visualization. The visualization component provides generic capabilities for visualizing geospatial web services from various domains. Current version supports displaying OGC WMS services. Two modes of visualization are supported: static and dynamic. The client is developed based on Microsoft’s AJAX plug-ins for the Bing Maps with a) Bing Maps serving as the background map for the SWP, and b) Bing Maps controlling visualization of service data. This paper is focused on the interface design and challenges in development. Experience and challenges are discussed to assist future developments in geospatial web service clients.