RedLightGreen was a database of bibliographic descriptions on the Web created by Research Libraries Group (RLG).
[1] It used a set of four million records extracted from OCLC's WorldCat database, and was designed to help novice users make selections from the vast bibliographic resources they would encounter in such a large set.
[2] RedLightGreen also allowed users to create citations for works found.
Work on RedLightGreen began in 2001 with funding from the Andrew W. Mellon Foundation.
[3] On 1 July 2006, RLG was merged with OCLC, and it was announced that the RedLightGreen service would be replaced by WorldCat, via Open WorldCat, available at WorldCat.org.