The National Library of Medicine has announced the debut of the NLM Catalog, a new Entrez database. The NLM Catalog provides access to NLM bibliographic data for over 1.2 million journals, books, audiovisuals, computer software, electronic resources, and other materials via the NCBI Entrez retrieval system. Supporting automated mapping features such as explosions on MeSH terms, the new database is an alternate search interface to the bibliographic records resident in LocatorPlus