The Research Libraries Group (RLG) was a U.S.-based library consortium that existed from 1974 until its merger with the OCLC library consortium in 2006. RLG developed the Eureka interlibrary search engine, the RedLightGreen database of bibliographic descriptions, and ArchiveGrid, a database containing descriptions of archival collections. It also developed a framework known as the "RLG Conspectus" for evaluating research library collections, which evolved into a set of descriptors used in library collection policy statements, last updated in 1997. The Library of Congress used the conspectus in 2015 in the revision of its own collection policy statement, and decided to retain this resource on its website, as a helpful scale for judging an academic collection's depth.