An OpenURL is similar to a web address, but instead of referring to a physical website, it refers to an article, book, patent, or other resource within a website. OpenURLs are similar to permalinks because they are permanently connected to a resource, regardless of which website the resource is connected to. Libraries and other resource centers are the most common place to find OpenURLs because an OpenURL can help Internet users find a copy of a resource that they may otherwise have limited access to. The source that generates an OpenURL is often a bibliographic citation or bibliographic record in a database. Examples of these databases include Ovid Technologies, Web of Science,

Chemical Abstracts Service CAS (formerly Chemical Abstracts Service) is a division of the American Chemical Society. It is a source of chemical information. CAS is located in Columbus, Ohio, United States. Print periodicals ''Chemical Abstracts'' is a periodical index th ...

, Modern Language Association and

Google Scholar Google Scholar is a freely accessible web search engine that indexes the full text or metadata of scholarly literature across an array of publishing formats and disciplines. Released in beta in November 2004, the Google Scholar index includes p ...

. The National Information Standards Organization (NISO) has developed standards for OpenURL and its data container as

American National Standards Institute The American National Standards Institute (ANSI ) is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organ ...

(ANSI) standard ANSI/NISO Z39.88-2004. OpenURL standards create a clear structure for links that go from information resource databases (sources) to library services (targets). A target is a resource or service that helps satisfy a user's information needs. Examples of targets include full-text repositories, online journals, online library catalogs and other Web resources and services. OpenURL knowledge bases provide links to the appropriate targets available.

History

OpenURL was created by

Herbert Van de Sompel Herbert Van de Sompel is a Belgian librarian, computer scientist, and musician, most known for his role in the development of the Open Archives Initiative (OAI) and standards such as OpenURL, Object Reuse and Exchange, and the OAI Protocol for Me ...

, a librarian at the University of Ghent, in the late 1990s. His link-server software,

SFX SFX may refer to: Entertainment * Special effects (usually visual), illusions used in film, television, and entertainment * Sound effects, sounds that are artificially created or enhanced * SFX (magazine), ''SFX'' (magazine), a British magazine c ...

, was purchased by the library automation company Ex Libris Group which popularized OpenURL in the information industry. In 2005, a revised version of OpenURL (version 1.0) became ANSI/NISO standard Z39.88-2004, with Van de Sompel's version designated as version 0.1. The new standard provided a framework for describing new formats, as well as defining XML versions of the various formats. In 2006 a research report found some problems affecting the efficiency of OpenURL linking and recommended the creation of a group to establish best practice solutions. The KBART ( Knowledge Bases And Related Tools) working group has been set up to progress the recommendations of the research report. OpenURL standards and reporting work continues with NISO's IOTA (Improving OpenURLs Through Analytics) project, which produced a reporting tool and research summary in 2013 noting the benefits of data analysis to improve link resolution. In June 2006, NISO designated the Online Computer Library Center (OCLC) as the "maintenance and registration agency" (or "registry agent") of the OpenURL standard, for an initial term of five years. In 2011, OCLC researchers highlighted their work in a NISO journal article, noting that "the OpenURL standard is one of the most heavily used NISO standards". As registry agent, OCLC was responsible for reviewing proposed extensions to the standard and maintaining a listing of those it approved. Per the standard, registry entries could specify particular metadata fields and their representation. The registry had the canonical URL http://www.openurl.info/registry. In 2022, OCLC updated its OpenURL Registry webpage to state that the registry is no longer supported or maintained, saying it had been an "experimental research project" and "research prototype application". The standard registry URL now redirects to an archived version of the site, described as "the Frozen (deprecated) version of the Registry for the OpenURL Framework".

Standards

* NISO OpenURL version 0.1 (2000-05-16) * NISO OpenURL version 1.0f (2003-03-18) * ANSI/NISO Z39.88-2004 * ANSI/NISO Z39.88-2004 2010ref name="NISO_2010"/>

Use

The most common application of OpenURL is to assist in the resolution of a request for a web resource (such as an online article). An OpenURL includes information about the referenced resource itself, and context information — both the context in which the OpenURL occurs (for example, a page of search results from a library catalog) and the context of the request (for example, the particular user making the request). If a different context is expressed in the URL, a different copy ends up resolved to. Changes in context are predictable, and do not require the original creator of the hyperlink (for example, the journal publisher) to handcraft different URLs for different contexts. For example, changing either the base URL or a parameter in the query string can mean that the OpenURL resolves to a copy of a resource in a different library. So the same OpenURL, contained for instance in an electronic journal, can be adjusted by any library to provide access to their own copy of the resource, without completely overwriting the journal's hyperlink. The journal provider, in turn, is no longer required to provide a different version of the journal, with different hyperlinks, for each subscribing library (See also

COinS A coin is a small, flat (usually depending on the country or value), round piece of metal or plastic used primarily as a medium of exchange or legal tender. They are standardized in weight, and produced in large quantities at a mint in order to ...

Format

An OpenURL consists of a base

URL A Uniform Resource Locator (URL), colloquially termed as a web address, is a reference to a web resource that specifies its location on a computer network and a mechanism for retrieving it. A URL is a specific type of Uniform Resource Identifie ...

, which contains the address of the user's institutional link-server, followed by a query string, consisting of key-value pairs serializing a ''ContextObject''. The ContextObject is most often bibliographic data, but as of version 1.0 OpenURL can also include information about the requester, the resource containing the

hyperlink In computing, a hyperlink, or simply a link, is a digital reference to data that the user can follow or be guided by clicking or tapping. A hyperlink points to a whole document or to a specific element within a document. Hypertext is text ...

, the type of service required, and so forth. For example: :http://resolver.example.edu/cgi?genre=book&isbn=0836218310&title=The+Far+Side+Gallery+3 is a version 0.1 OpenURL describing a book. http://resolver.example.edu/cgi is the base URL of an example link-server. In version 1.0, this same link becomes somewhat longer: :

http://resolver.example.edu/cgi?ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:book&rft.isbn=0836218310&rft.btitle=The+Far+Side+Gallery+3

The above query string consists of the following key-value pairs: * ctx_ver=Z39.88-2004 – specifying the ContextObject version * rft_val_fmt=info:ofi/fmt:kev:mtx:book – specifying the metadata format for the referent (in this case, a book) * Fields from this format describing the referent object: ** rft.isbn=0836218310 – the

ISBN The International Standard Book Number (ISBN) is a numeric commercial book identifier that is intended to be unique. Publishers purchase ISBNs from an affiliate of the International ISBN Agency. An ISBN is assigned to each separate edition an ...

identifying the book ** rft.btitle=The+Far+Side+Gallery+3 – the title of the book Keys always consist of safe characters and are not encoded, but values are URL-encoded.

Applications and tools

Several companies market link server systems. Some proprietary options include

OCLC OCLC, Inc., doing business as OCLC, See also: is an American nonprofit cooperative organization "that provides shared technology services, original research, and community programs for its membership and the library community at large". It wa ...

(as part o
WorldCat Local
, Ex Libris (

and Alma UResolver), Serials Solutions
360 Link
, formerly known as Article Linker), Innovative Interfaces, Inc. (WebBridge), EBSCO Information Services
Full Text Finder
,

Ovid Pūblius Ovidius Nāsō (; 20 March 43 BC – 17/18 AD), known in English as Ovid ( ), was a Roman poet who lived during the reign of Augustus. He was a contemporary of the older Virgil and Horace, with whom he is often ranked as one of the ...

(LinkSolver),

SirsiDynix SirsiDynix is a United States company which produces integrated library system (ILS) software and associated services for libraries. Origins The Sirsi Corporation was founded in Huntsville, Alabama in 1979 by Mike Murdock, Jacky Young, and Jim Yo ...

(Resolver), Fretwell-Downing (OL2)
TDNet
Inc. (TOUResolver), WT Cox Information Services

, R. R. Bowker (Ulrichs Resource Linker) and Infor (Vlink). Open-source link resolvers includ
CUFTS
and Umlaut. There are also open-source tools for manipulating OpenURLs and th
Code4Lib
community maintains a list of these. OpenURL is usually implemented by information providers by dynamically inserting an appropriate base URL into web pages sent to an authenticated user. OpenURL

is a specification that allows free services like

Wikipedia Wikipedia is a multilingual free online encyclopedia written and maintained by a community of volunteers, known as Wikipedians, through open collaboration and using a wiki-based editing system. Wikipedia is the largest and most-read ref ...

to provide OpenURLs by cooperating with client side software agents.

Federated search Federated search retrieves information from a variety of sources via a search application built on top of one or more search engines. A user makes a single query request which is distributed to the search engines, databases or other query engine ...

software presents OpenURL links in record fields by employing the library's subscriber links to link servers facilitating access to full-text resources from bibliographic record hyperlinks.

References

External links

Registry for the OpenURL Framework – ANSI/NISO Z39.88-2004

OpenURL standardization committee
- archives of [email protected] mailing list
Umlaut
Internet architecture Library automation Library science