The National Science, Mathematics, Engineering, and Technology Education Digital Library (NSDL) is the National Science Foundation's (NSF) ongoing effort to build a comprehensive science digital library. In this article (published in January 2002 D-Lib Magazine) the Cornell University team lead by William Arms describes the preliminary work done to develop a working model for NSDL. Note: For information on the Internet Scout Project's involvement in NSDL, see http://scout.cs.wisc.edu/nsdl-reports/. [DJS]