View source for Open file format

{{short description|Published specification for storing digital data}}
{{redirect|Open format|the competition format used in sport tournaments|Open (sport)}}
{{distinguish|Open data}}
{{Prose|date=October 2024}}
{{Use dmy dates|date=January 2024}}

An '''open file format''' is a [[file format]] for storing [[Data (computing)|digital data]],<ref name=":0" /><ref>{{Cite web |title=Open Format Definition |url=https://techterms.com/definition/open_format |access-date=2022-03-24 |website=techterms.com}}</ref> defined by an openly published [[specification]] usually maintained by a [[standards organization]], and which can be used and implemented by anyone. An open file format is licensed with an [[open license]].<ref>{{Cite web |title=Open Format Definition - Open Definition - Defining Open in Open Data, Open Content and Open Knowledge |url=https://opendefinition.org/ofd/ |access-date=2022-03-24 |website=opendefinition.org}}</ref><ref>{{cite web |title=open format - open data handbook |url=https://opendatahandbook.org/glossary/en/terms/open-format/}}</ref>{{Failed verification |reason=A possible mandatory connection between open file format and open licenses is not explicitly stated in any of the open format definitions in these references. |date=April 2024}}
{{Contradictory inline|section=The Linux Information Project|date=March 2024}}
For example, an open format can be implemented by both [[proprietary software|proprietary]] and [[free software|free]] and [[open-source software]], using the typical [[software license]]s used by each. In contrast to open file formats, [[Proprietary file format|closed file formats]] are considered trade secrets.

Depending on the definition, the specification of an open format may require a fee to access or, very rarely, contain other restrictions.<ref name="Free File Format Definition">{{cite web |title=Free File Format Definition |url=http://www.linfo.org/free_file_format.html |access-date=11 February 2007 |publisher=LINFO.org}}</ref> The range of meanings is similar to that of the term [[open standard]].

==Specific definitions==

===UK government===
In 2012 the UK Government created the policy Open Standards Principles, stating that the Open Standards Principles apply to every aspect of government IT and that Government technology must remain open to everyone.<ref name="Open Standards Principles">{{Cite web|date=2018-04-05|title=Open Standards principles|url=https://www.gov.uk/government/publications/open-standards-principles/open-standards-principles|access-date=2021-09-10|website=Gov.UK}}  [[File:Open Government Licence logo.svg|30px]] Text was copied from this source, which is available under an [http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/  Open Government Licence v3.0]. © Crown copyright.</ref> They have seven principles for selecting open standards for use in government, following these principals many open formats were adopted, notably [[OpenDocument|Open Document Format (ODF)]]. The seven principles for selecting open standards for use in the UK government are:

* Open standards must meet user needs
* Open standards must give suppliers equal access to government contracts
* Open standards must support flexibility and change
* Open standards must support sustainable cost
* Select open standards using well-informed decisions
* Select open standards using fair and transparent processes
* Specify and implement open standards using fair and transparent processes<ref name="Open Standards Principles"/>

===US government===
Within the framework of [[Open Government Initiative]], the [[federal government of the United States]] adopted the [[Data.gov#Open Government Directive|Open Government Directive]], according to which: "An open format is one that is platform independent, machine readable, and made available to the public without restrictions that would impede the re-use of that information".<ref>{{cite web|url=https://obamawhitehouse.archives.gov/open/documents/open-government-directive|title=Open Government Directive|work=The White House |date=December 8, 2009 |first1=Peter R. |last1=Orszag }}</ref>

===State of Minnesota===
The [[Minnesota|State of Minnesota]] defines the criteria for open, XML-based file formats as follows:<ref>{{Cite web |last=Updegrove |first=Andy |date=2007-02-06 |title=Meanwhile, Deep Down in Texas: An Open Format Bill is Filed |url=https://www.consortiuminfo.org/opendocument-and-ooxml/meanwhile-deep-down-in-texas-an-open-format-bill-is-filed/ |access-date=2023-11-23 |website=ConsortiumInfo.org |language=en-US}}</ref>

* The format is interoperable among diverse internal and external platforms and applications
* The format is fully published and available royalty-free
* The format is implemented by multiple vendors
* The format is controlled by an open industry organization with a well-defined inclusive process for evolution of the standard

===Commonwealth of Massachusetts===
The [[Massachusetts|Commonwealth of Massachusetts]] "defines open formats as specifications for data file formats that are based on an underlying open standard, developed by an open community, affirmed and maintained by a standards body and are fully documented and publicly available."<ref>"[http://xml.coverpages.org/ni2007-07-03-a.html Major Revision of Massachusetts Enterprise Technical Reference Model (ETRM).]" Robin Cover, Editor – 3 July 2007 – Cover Pages.</ref>

The Enterprise Technical Reference Model (ETRM) classifies four formats as "Open Formats":
#[[OpenDocument|OASIS Open Document Format For Office Applications (OpenDocument) v. 1.1]]
#[[Office Open XML|Ecma-376 Office Open XML Formats (Open XML)]]
#[[HTML|Hypertext Document Format v. 4.01]]
#[[plain text|Plain Text Format]]

===Sun Microsystems===
[[Sun Microsystems]] defined the criteria for open formats as follows:<ref name=":0">[https://web.archive.org/web/20060924102321/http://www.xml.gov/presentations/sun/odf.pdf Open Document Format for Office Applications (OpenDocument) v1.0] – OASIS Standard, 1 May 2005</ref>
* The format is based on an underlying open standard
* The format is developed through a publicly visible, community-driven process
* The format is affirmed and maintained by a vendor-independent standards organization
* The format is fully documented and publicly available
* The format does not contain proprietary extensions

===The Linux Information Project===
According to [[The Linux Information Project]], the term ''open format'' should refer to "any format that is published for anyone to read and study but which may or may not be encumbered by patents, copyrights or other restrictions on use"<ref name="Free File Format Definition"/> – as opposed to a ''free format'' which is ''not'' encumbered by any copyrights, patents, trademarks or other restrictions.

==Examples of open formats==
{{See main|List of open file formats}}

Open formats (in the royalty-free and free access sense) include:<ref name="Free File Format Definition"/>
* [[PNG]] — a [[Raster graphics|raster image]] format originally standardized by [[International Organization for Standardization|ISO]]/[[International Electrotechnical Commission|IEC]] and as an informational [[Internet Engineering Task Force|IETF]] RFC but from June 24, 2025 by [[World Wide Web Consortium|W3C]].
* [[FLAC]] — [[Data compression|lossless audio]] [[codec]]
* [[WebM]] — a video/audio container format
* [[HTML]] — is the main markup language for creating web pages and other information that can be displayed in a web browser.
* [[gzip]] — for compression
* [[CSS]] — style sheet format usually used with (X)HTML, standardized by [[W3C]]

The following formats are open (royalty-free with a one-time fee on the standard):
* [[Office Open XML]]: the ECMA version is downloadable for no charge, but the newer ISO versions require a fee;
* [[OpenDocument]]: As adopted by the UK Government in 2012 to meet their open standards principles, for Government technology to remain open to everyone.
* [[C (programming language)|C language]]: royalty-free, but ISO standard requires a fee (drafts available for no charge);
* [[PDF]]: an ISO-standardized file format for reliable document exchange across platforms;

==See also==
{{Portal|Free and open-source software}}
* [[Open standard]]
* [[Open source]]
* [[Openness]]
* [[Embrace, extend, and extinguish]]
* [[List of open-source codecs]]
* [[Open educational resources]]
* [[Open system (computing)|Open system]]
* [[Free content]]
* [[Network effect]]
* [[Proprietary file format]]
* [[Vendor lock-in]]

==References==
{{Reflist}}

==External links==
{{Wikiversity}}
{{Wikibooks|FOSS Open Standards}}
*[https://web.archive.org/web/20081012161213/http://www.openformats.org/ OpenFormats]
*[https://help.ubuntu.com/community/FreeFormats Practical Advice for using Free Formats from Ubuntu Community Documentation]
*[https://web.archive.org/web/20090929011410/http://ec.europa.eu/enterprise/sectors/ict/files/2006-11-20-flossimpact_en.pdf Study on the: Economic impact of open source software on innovation and the competitiveness of the Information and Communication Technologies (ICT) sector in the EU, 2006] EU report in favor of adopting open source software
* [http://www.linfo.org/free_file_format.html Free File Format Definition]
* [http://freedomdefined.org/Definition Definition of Free Cultural Works]
{{Computer files}}

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[[Category:Computer file formats]]
[[Category:Open standards| ]]