INSTAR (INteractive STream Assessment Resource) is a dynamic and interactive internet application built on ESRI’s ArcIMS platform and supported by dedicated servers at Virginia Commonwealth University’s Center for Environmental Studies. INSTAR allows users to access and manipulate a comprehensive (and growing) database representing over 2,000 stream and river collections statewide.  Accessible data represent fish and macroinvertebrate assemblages, instream habitat, and stream geomorphology. The application supports user-driven database queries, mapping functions, and quantitative biological assessments of stream reaches and watersheds, using algorithms and ecological models that compare user-selected sites to appropriate regional reference conditions. INSTAR is accessible from most computers via the internet and navigation throughout the application is relatively easy. For more information, download a presentation in Adobe PDF.