MEDLINE (Medical Literature Analysis and Retrieval System Online) is a comprehensive bibliographic database of life sciences and biomedical information, maintained by the United States National Library of Medicine (NLM). It indexes articles from thousands of academic journals covering medicine, nursing, pharmacy, and various biological fields.
Its history began with MEDLARS (Medical Literature Analysis and Retrieval System), launched by the NLM in 1964 as the world's first large-scale, computer-based search service, designed to mechanize the manual compilation of Index Medicus. An online version, also called MEDLINE, became available to medical libraries in 1971, but direct public access was limited.
A significant milestone occurred in 1997 when the NLM deployed PubMed, offering free, web-based MEDLINE searches directly to the general online user, revolutionizing access to medical literature. Today, MEDLINE contains over 38 million records from more than 5,200 publications, with content dating back to 1781 and continuously updated. It remains a vital, freely accessible resource for researchers and the public worldwide through the PubMed interface.