|Nonprofit membership cooperative|
|Headquarters||Dublin, Ohio, United States|
|Skip Prichard, President and CEO|
Over 72,000 libraries, archives
and museums in 170 countries 
The Online Computer Library Center, Inc. (OCLC) is "a nonprofit, membership, computer library service and research organization dedicated to the public purposes of furthering access to the world's information and reducing information costs". Founded in 1967 as the Ohio College Library Center, OCLC and its member libraries cooperatively produce and maintain WorldCat, the largest online public access catalog (OPAC) in the world.
- History 1
- Services 2
- Research 3
- Advocacy 4
- Online database: WorldCat 5
- Identifiers and linked data 6
- Company acquisitions 7
- Criticism 8
- See also 9
- References 10
- Further reading 11
- External links 12
Originally named the Ohio College Library Center, OCLC began in 1967 through a collaboration of Ohio university presidents, vice presidents, and library directors who wanted to create a cooperative, computerized network for Ohio libraries. The group first met on July 5, 1967 on the campus of
- Official website
- Open WorldCat Program
- Works by or about OCLC in libraries (WorldCat catalog)
- Coyle, Karen (Dec 22, 2011). "National Library of Sweden and OCLC fail to agree". Coyle's InFormation.
- Spalding, Tim (February 23, 2009). "Research libraries clobber OCLC Policy". Thingology Blog. Library Thing.
- "Cooperation". OCLC. Retrieved 2010-03-18.
- "About OCLC". OCLC. Retrieved 2010-03-18.
- "In the beginning". Retrieved 2012-08-28.
- Intner, Sheila (March–April 2007). "The Passing of an Era". Technicalities 27 (2): 1, 13–14. Retrieved 2012-08-28.
- Jordan, Jay (2010). Bates, Marcia J., ed. Encyclopedia of Library and Information Sciences V (3rd ed.). New York: CRC Press. p. 3924.
- Bailey-Hainer, Brenda (2009). "The OCLC Network of Regional Service Providers: The Last 10 Years". Journal of Library Administration.
- O'Neill, Nancy (Nov–Dec 2004). "Open WorldCat Pilot: A User's Perspective.". Searcher 12 (10). Retrieved 8 March 2015.
- "WikiD". Retrieved 5 March 2015.
- "deweybrowser.oclc.org". deweybrowser.oclc.org. Retrieved 2014-04-30.
- "Preservation Service Center". OCLC. Archived from the original on 2003-12-29.
- "QuestionPoint". OCLC. 17 February 2014. Retrieved 2014-04-30.
- "OCLC prints last library catalog cards". OCLC. 1 October 2015. Retrieved 2 October 2015.
- Hyatt, S.; Young, J. A. (March 2005). "OCLC Research Publications Repository". D-Lib Magazine 11 (3).
- "OCLC Publications". Retrieved 2012-08-28.
- "OCLC Membership Reports". Retrieved 2012-08-28.
- "OCLC Presentations". Retrieved 2012-08-28.
- De Rosa, C. (2009). "Advocacy and OCLC". Journal of Library Administration 49 (7): 719–726.
- "See also" Grossman, Wendy M (January 21, 2009). "Why you can't find a library book in your search engine". The Guardian. Retrieved Sep 15, 2014.
- "WebJunction". Oclc.org. Retrieved 2014-04-30.
- "Advocacy: From Awareness to Funding, the next chapter".
- "A global library resource". oclc.org.
- "First search".
- "Open WorldCat". Worldcat.org. Retrieved 2014-04-30.
- Wallis, Richard (24 September 2013). "OCLC Declare OCLC Control Numbers Public Domain".
- "OCLC Control Number". Retrieved 2014-01-03.
- HangingTogether.org (11 October 2013). "OCLC Control Numbers in the Wild".
- Jordan, Jay (17 March 2010). "Letter to members 2010". OCLC. Archived from the original on 2010-03-26.
- Rogers, Michael (30 October 2007). "CLC/OCLC Pica Merge". Library Journal (New York).
- "OCLC acquires EZproxy authentication and access software" (Press release). Dublin, OH: OCLC. 11 January 2008.
- Price, Gary (13 January 2015). "Print Collections: OCLC Acquires Sustainable Collection Services". Infodocket. Retrieved 6 March 2015.
- "Mergers and Acquisitions". Retrieved 6 March 2015.
- Beall, Jeffrey (2008). "OCLC: A Review". In Roberto, K.R. Radical Cataloging: Essays at the Front. Jefferson, NC:
- Coyle, Karen (29 July 2010). "SkyRiver Sues OCLC over Anti-Trust". Karen Coyle.
- Breeding, Marshall (29 July 2010). "SkyRiver and Innovative Interfaces File Major Antitrust Lawsuit Against OCLC".
- Price, Gary (4 March 2013). "III Drops OCLC Suit, Will Absorb SkyRiver".
OCLC has been criticized for monopolistic practices. In July 2010, the company was sued by SkyRiver, a rival startup, in an antitrust suit. Library automation company Innovative Interfaces joined SkyRiver in the suit. The suit was dropped in March 2013, however, following the acquisition of SkyRiver by Innovative Interfaces.
 Other mergers and acquisitions are listed on the OCLC website. OCLC acquired
OCLC also runs the Virtual International Authority File (VIAF), an international name authority file. VIAF numbers are broadly used as standard idenfitiers.
OCNs are particularly useful as identifiers for books and other bibliographic materials that do not have ISBN numbers (e.g., books published before 1970). OCNs are used as identifiers often in WorldHeritage and Wikidata. In October 2013, it was reported that out of 29,673 instances of Infobox Book in WorldHeritage, "there were 23,304 ISBNs and 15,226 OCNs"; and regarding Wikidata: "of around 14 million Wikidata items, 28,741 were books. 5403 Wikidata items have an ISBN-13 associated with them, and 12,262 have OCNs."
OCLC assigns a unique control number (referred to as an "OCN" for "OCLC Control Number") to each new bibliographic record in the WorldCat. Numbers are assigned serially, and as of mid-2013 over a billion OCNs had been created. In September 2013, the OCLC declared these numbers to be in the public domain, removing a perceived barrier to widespread use of OCNs outside of OCLC itself. The control numbers link WorldCat's records to local library system records by providing a common reference key for a record across libraries.
- See for ways to use OCLC links in references.
WorldCat is available to the public for searching via a subscription web-based service called FirstSearch, as well as through the publicly available WorldCat.org.
As of March 2015, the OCLC database contained over 336M records with 2.2 billion cataloged items, and is the world's largest bibliographic database covering 72,000 libraries. Connexion is available to professional librarians as a computer program or on the web at connexion.oclc.org.
WorldCat contains records in MAchine Readable Cataloging (MARC) format contributed by library catalogers worldwide who use OCLC as a cataloging tool. These MARC format records are then downloaded into the libraries' local catalog systems. This allows libraries to find and download records for materials to add to their local catalog without the lengthy process of cataloging each individually.
OCLC has a database, WorldCat, for cataloging and searching purposes which is used by librarians and the public. Contributions to WorldCat are made via a computer program, Connexion, which was introduced in 2001; the Connexion predecessor, OCLC Passport, was phased out in May 2005.
- See WorldCat entry
Online database: WorldCat
OCLC partnered with search engine providers in 2003 in order to advocate for libraries and share information across the broadest possible Internet landscape. Google, Yahoo!, and Ask.com have all collaborated with OCLC in order to make the WorldCat records searchable through those search engines.
Other past advocacy campaigns have focused on sharing the knowledge gained from library and information research. Such projects have included communities such as the metadata standards that support a broad range of purposes and business models."
OCLC's most recent advocacy campaign, "Geek the Library," highlights the vital role of public libraries in the current challenging environment. One goal of this community-based public awareness campaign is to increase local library support by encouraging the public to share what they 'geek', using the word as a verb. The idea is that every person has a passion that they 'geek' from modern art to chemical engineering, and that the library supports all of the passions in the community. The campaign, funded by a grant from the Bill & Melinda Gates Foundation, uses a strategy based on the findings of the 2008 OCLC report, "From Awareness to Funding: A study of library support in America."
WebJunction is a division of OCLC funded by a grant from the Bill and Melinda Gates Foundation, which provides training services to librarians.
Advocacy has been a part of OCLC's mission since its founding in 1967. OCLC staff members meet and work regularly with library leaders, information professionals, researchers, entrepreneurs, political leaders, trustees, students and patrons to advocate "advancing research, scholarship, education, community development, information access, and global cooperation."
- OCLC Publications – Research articles from various journals including, but not limited to, Code4Lib Journal, OCLC Research, Reference & User Services Quarterly, College & Research Libraries News, Art Libraries Journal, and National Education Association Newsletter. The most recent publications are displayed first, and all archived resources, starting in 1970, are also available.
- Membership Reports – A number of significant reports on topics ranging from virtual reference in libraries to perceptions about library funding.
- Newsletters – Current and archived newsletters for the library and archive community.
- Presentations – Presentations from both guest speakers and OCLC research from conferences, webcasts, and other events. The presentations are organized into five categories: Conference presentations, Dewey presentations, Distinguished Seminar Series, Guest presentations, and Research staff presentations.
OCLC has been conducting research for the library community for more than 30 years. In accordance with its mission, OCLC makes its research outcomes known through various publications. These publications, including journal articles, reports, newsletters, and presentations, are available through the organization's website.
OCLC produced catalog cards for member libraries began in 1971 with its shared online catalog; the company printed its last catalog cards on October 1, 2015.
The reference management service QuestionPoint provides libraries with tools to communicate with users. This around-the-clock reference service is provided by a cooperative of participating global libraries.
Until August 2009, when it was sold to Backstage Library Works, OCLC owned a preservation microfilm and digitization operation called the OCLC Preservation Service Center, with its principal office in Bethlehem, Pennsylvania, U.S.
The Online Computer Library Center acquired the trademark and copyrights associated with the Dewey Decimal Classification System when it bought Forest Press in 1988. A browser for books with their Dewey Decimal Classifications is also available; it is currently in beta form.
OCLC and its member libraries cooperatively produce and maintain wiki project, WikiD, allowing readers to add commentary and structured-field information associated with any WorldCat record. WikiD was later phased out.
As OCLC expanded services in the United States outside of Ohio, it relied on establishing strategic partnerships with "networks," organizations that provided training, support and marketing services. By 2008, there were 15 independent United States regional service providers. OCLC networks played a key role in OCLC governance, with networks electing delegates to serve on OCLC Members Council. During 2008, OCLC commissioned two studies to look at distribution channels; at the same time, the OCLC Members Council approved governance changes that had been recommended by the Board of Trustees which severed the tie between the networks and governance. In early 2009, OCLC negotiated new contracts with the former networks and opened a centralized support center.
Membership in OCLC is based on use of services and contribution of data. Between 1967 and 1977, OCLC membership was limited to institutions in Ohio, but in 1978, a new governance structure was established that allowed institutions from other states to join. In 2002, the governance structure was again modified to accommodate participation from outside the United States.
 at Ohio University on August 26, 1971. This was the first occurrence of online cataloging by any library worldwide.Alden Library Kilgour wished to merge the latest information storage and retrieval system of the time, the computer, with the oldest, the library. The plan was to merge the catalogs of Ohio libraries electronically through a computer network and database in order to streamline operations, control costs, and increase efficiency in library management. The goal of this network and database was to bring libraries together to cooperatively keep track of the world's information in order to best serve researchers and scholars. The first library to do online cataloging through OCLC was the  medical school librarian, to design the shared cataloging system.Yale University, a former Frederick G. Kilgour The group hired