WorldCat (Public Version) WorldCat (the OCLC Online Union Catalog) is the world's most comprehensive bibliography containing millions of bibliographic records cataloged by OCLC member libraries. It includes books, websites and internet resources, manuscripts, maps, computer programs, musical scores, films and slides, newspapers, journals and magazines, sound recordings, articles, chapters, papers, and videotapes. Coverage from before 1000BC to present, updated daily.