The National Center for Biotechnology Information (NCBI) at the National Institutes of Health was created in 1988 to develop information systems for molecular biology. In addition to maintaining the GenBank® (1) nucleic acid sequence database, which receives data through the international collaboration with DDBJ and EMBL as well as from the scientific community, NCBI provides data retrieval systems and computational resources for the analysis of GenBank data and many other kinds of other biological data. For the purposes of this article, the NCBI suite of resources is grouped into nine broad categories that are discussed after a summary of recent developments. All resources discussed are available from the NCBI home page at www.ncbi.nlm.nih.gov and can be located using the Entrez Site Search database. In most cases, the data underlying these resources and executables for the software described are available for download at ftp.ncbi.nih.gov.
