Socioeconomic Data and Applications Center (SEDAC) Map Client is a web-based mapping tool that allows flexible interaction with spatial data from CIESINs SEDAC and other sources. The map client may be used to explore SEDAC global data holdings, organized by themes of human-environment interactions. In the clients advanced mode, users may import data of their own or access data available from ... other online data services. One of the clients unique features is the ability to save for future use a specific set of map layers and view of the data - a &Web map context&. The &context file& can be shared with other users who can then open up and work with the same interactive map from their own Internet browser. The client has a number of pre-set contexts that enable users to quickly generate maps for specific themes and world regions. The integrated visualization, analysis, and display of geospatial data will be of primary interest to fundamental and applied researchers, operational users, and public policy experts in the social and earth sciences. The service is provided by the Columbia University Center for International Earth Science Information Network (CIESIN) in collaboration with Ionic Software®.