In 2001, WorldCat, the primary international bibliographic utility, contained 45 million records with over 750 million library location listings. These records span over 4,000 years of recorded knowledge in 377 languages. Under the auspices of an OCLC/ALISE (Online Computer Library Center/Association of Library and Information Science Educators) research grant, a bibliometric study was conducted of WorldCat. A 10% systematic random sample of the database was analyzed utilizing the OCLC iCAS product to profile the monographic bibliographic records in WorldCat by type of library, subject, language, and publication date parameters. The profile details the information commons of global publication made accessible through the OCLC international network. There were 3,378,272 usable records from the 10% systematic random sample of which 2,199,165 records had call numbers and could be analyzed by subject. Five types of library groupings were established for the study: research, academic, public, special, and school. The research libraries grouping has the largest number or records in the sample with call numbers at 1,745,034. The missions of the different types of libraries can be discerned in the subject profiles for each library grouping. Among the findings of the study are that the profile of WorldCat by time period and by subject divisions is mirrored in the profile of the grouping of research libraries. Of all of the records in the 10% sample, approximately 65% are English language materials with 35% for foreign language materials. The analysis by number of unique records and title overlap demonstrate that the universe of materials under bibliographic control in WorldCat shows a high level of diversity of resources with 53% of records having only one library location symbol. The number of records in the analysis show a sharp decline by most measures from 1992 to the last imprint year in the study. An analysis was performed of the records in the sample with ISBN numbers, finding that only 21% of the 3 million plus records in the study had ISBN numbers. This can be due to the amount of retrospective titles published before the numbering system came into use and also the number of publications that are not from mainstream publishers. But for publications since 1970, 57% of all records with call numbers have ISBN numbers, leaving an intriguing 43% of records with call numbers that do not have ISBN numbers. The findings establish that WorldCat is a rich resource for cataloging records, verification of the existence of titles, and identifying prospective materials for resources sharing. As OCLC continues to implement its Global Strategy, Extending the Cooperative, the number of international members and thus foreign language records and unique titles may continue to increase. (Contains 47 tables, 9 figures, and 30 references.) (Author)