NLM Gateway allows users to search in multiple retrieval systems at the U.S. National Library of Medicine (NLM). The current Gateway searches MEDLINE/PubMed, OLDMEDLINE, LOCATORplus, MEDLINEplus, ClinicalTrials.gov, DIRLINE, Meeting Abstracts, and HSRProj. Useful to physicians, researchers, students and the general public for an overall search of NLM's information resources.