The National Geophysical Data Center's innovative Space Physics Interactive Data Resource (SPIDR) is a multidisciplinary on-line system to search, browse, and access space weather and environmental data sets over the Internet. SPIDR is a tool for the online user to select data or imagery by date and geographical location and deliver an image to the user over the World Wide Web. Currently, Defense Meteorological Satellite Program (DMSP) satellite imagery, geomagnetic variations, ionospheric vertical incidence databases, and NOAA Goestationary Operational Environmental Satellites (GOES) space environment monitor data can be accessed by SPIDR. DMSP visible, infrared, and microwave imagery displays aurora, city lights, fires, lightning strikes, and cloud coverage. Ionospheric and geomagnetic data, as well as GOES X ray, energetic particle, and the magnetic field at the spacecraft, can be plotted from interactive menus. Solar and geomagnetic indices can be generated as plots for comparison. The Web user selects the month and year from pull-down menus and clicks the worldwide map in the region of interest. Worldwide contour maps of maximum electron density can also be generated from a global model of the ionosphere.