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
A permalink or permanent link is a URL that is intended to remain unchanged for many years into the future, yielding a hyperlink that is less susceptible to link rot. Permalinks are often rendered simply, that is, as clean URLs, to be easier to ...
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
Ovid Technologies, Inc. (or just Ovid for short), part of the Wolters Kluwer group of companies, provides access to online bibliographic databases, academic journals, and other products, chiefly in the area of health sciences. The National Libr ...
,
Web of Science
The Web of Science (WoS; previously known as Web of Knowledge) is a paid-access platform that provides (typically via the internet) access to multiple databases that provide reference and citation data from academic journals, conference proceedi ...
,
Chemical Abstracts Service
Chemical Abstracts Service (CAS) is a division of the American Chemical Society. It is a source of chemical information and is located in Columbus, Ohio, United States.
Print periodicals
''Chemical Abstracts'' is a periodical index that provid ...
,
Modern Language Association
The Modern Language Association of America, often referred to as the Modern Language Association (MLA), is widely considered the principal professional association in the United States for scholars of language and literature. The MLA aims to "str ...
and
Google Scholar
Google Scholar is a freely accessible web search engine that indexes the full text or metadata of Academic publishing, scholarly literature across an array of publishing formats and disciplines. Released in Beta release, beta in November 2004, th ...
.
The
National Information Standards Organization
The National Information Standards Organization (NISO; ) is a United States non-profit standards organization that develops, maintains and publishes technical standards related to publishing, bibliographic and library applications. It was found ...
(NISO) has developed standards for OpenURL and its data container as
American National Standards Institute
The American National Standards Institute (ANSI ) is a private nonprofit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organiz ...
(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 ...
, a librarian at the
University of Ghent
Ghent University (, abbreviated as UGent) is a Public university, public research university located in Ghent, in the East Flanders province of Belgium.
Located in Flanders, Ghent University is the second largest Belgian university, consisting o ...
, in the late 1990s. His link-server software, SFX, was purchased by the library automation company
Ex Libris Group
Ex Libris Group is an Israeli software company that develops integrated library systems and other library software. Their headquarters is in the Malha Technology Park in southwestern Jerusalem. It has ten other offices around the world. In Octobe ...
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
Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing data. It defines a set of rules for encoding electronic document, documents in a format that is both human-readable and Machine-r ...
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
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 re ...
) 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, Inc. 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 was founded in 1967 as the ...
(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
2010
The year saw a multitude of natural and environmental disasters such as the 2010 Haiti earthquake, the Deepwater Horizon oil spill, and the 2010 Chile earthquake. The 2009 swine flu pandemic, swine flu pandemic which began the previous year ...
ref 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 object, usually round and flat, 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 facilitate trade. They are most often issued by ...
).
Format
An OpenURL consists of a base
URL
A uniform resource locator (URL), colloquially known as an address on the Web, is a reference to a resource that specifies its location on a computer network and a mechanism for retrieving it. A URL is a specific type of Uniform Resource Identi ...
, which contains the address of the user's institutional link-server, followed by a
query string
A query string is a part of a uniform resource locator ( URL) that assigns values to specified parameters. A query string commonly includes fields added to a base URL by a Web browser or other client application, for example as part of an HTML doc ...
, 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 providing direct access to Data (computing), data by a user (computing), user's point and click, clicking or touchscreen, tapping. A hyperlink points to a whole document or to ...
, 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 or receive ISBNs from an affiliate of the International ISBN Agency.
A different ISBN is assigned to e ...
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