In June 2003, the Unidata Users Committee and COMET sponsored a workshop entitled "Expanding Horizons: Using Environmental Data for Education, Research, and Decision Making". The workshop provided hands-on sessions as well as lectures. Specifically, the workshop offered presentations of exemplary uses of Unidata software and GIS tools in research and teaching, cases studies of the use of environmental data with Unidata-supported tools and GIS-related tools, and community-building between traditional Unidata users and the wider GIS community.