NLM is the world's largest biomedical library, with a collection of over 4.9 million items. NLM is a national resource for all U.S. health sciences libraries and fills over 1/4 million interlibrary loan requests each year for these libraries. The Library is open to the public, but its collection is designed primarily for health professionals. The Library collects materials comprehensively in all major areas of the health sciences. Housed within the Library is one of the world's finest medical history collections of pre-1914 and rare medical texts, manuscripts, and incunabula. Most materials are in areas which are closed to the public (closed stacks), and may be requested for use in the appropriate Reading Room. Individuals may not borrow materials from the Library. The National Library of Medicine has extended its Internet reference services to cover inquiries concerning the history of medicine. Questions only concerning that subject can be sent to: hmdref@nlm.nih.gov. [description by NLM]

NLM offers WWW server, telnet services (free access to NLM library database and HSTAT; on subscription access to other databases maintained as part of the Medlars or Toxnet service (access to the AIDS databases and Dirline free (though both require prior registration)). Databases are also available via a user-friendly interface called Grateful Med.

Information services include:

(a) Locator: the NLM library catalogue.

(b) Medline: journal article database (see separate entry)

(c) Medlars: collection of biomedical databases, accessible on subscription to NLM or to national host (e.g. the British Library in UK). Databases are: Aidsdrugs, Aidsline, Aidstrials, Avline, Bioethicsline, Biotechseek, Cancerlit, Catline, Chemid, Chemline, Dentalproj, Dirline, Docuser, Health, Histline, Medline, PDQ, Popline, Sdiline, Serline, Toxline, Toxlit, Toxnet (see separate entries for some of these)

(d) Toxnet: collection of databases on toxicology and pollution, accessible on subscription (see separate entry)

(e) Health Services/Technology Assessment Text (HSTAT): full text collection of guidelines (see separate entry)

(f) National Center for Biotechnology Information (NCBI): see separate entry

(g) Dirline: directory of health and biomedical organisations, (primarily in the USA) providing information. Accessible free (on registration). Incorporate material from the Directory of Biotech Information

(h) WWW service has background information on the NLM, its products and contact information