{{for|the "OpenSearch" branded fork of Elasticsearch|OpenSearch (software)}}
{{Infobox file format
| child =
| name = OpenSearch
| icon =
| logo =
| screenshot = [[Image:Dewiki-searchplugin-blueish-autodiscovery.png|300px]]
| caption = Example of a web page which offers to add a new search plugin. With Firefox, the symbol of the currently selected search engine becomes bluish. The user can add the search engine offered by that page by clicking the triangle.
| extension =
| mime =
| type code =
| uniform type =
| magic =
| owner = [[Amazon.com]]
| released = {{Start date|2005|03|15}}
| latest release version = 1.1 Draft 6<ref>{{cite web|url=https://github.com/dewitt/opensearch/blob/master/opensearch-1-1-draft-6.md|title=OpenSearch 1.1 Draft 6|date=2019-12-08|access-date=2020-05-21}}</ref>
| latest release date = {{Start date and age|2005|12|06}}
| genre = [[Web syndication]]
| container for =
| contained by =
| extended from = [[RSS]]
| extended to =
| standard =
| free = [[Creative Commons license|Creative Commons Attribution-ShareAlike 2.5]]
| url = {{URL|https://github.com/dewitt/opensearch}}
}}
'''OpenSearch''' is a collection of technologies that allow the publishing of search results in a format suitable for [[web syndication|syndication]] and [[Search aggregator|aggregation]]. Introduced in 2005, it is a way for [[website]]s and [[search engine]]s to publish search results in a standard and accessible format.
OpenSearch was developed by [[Amazon.com]] subsidiary [[A9.com|A9]] and the first version, OpenSearch 1.0, was unveiled by [[Jeff Bezos]] at the ''O'Reilly Emerging Technology Conference'' on 15 March, 2005.<ref>{{cite web|url=http://conferences.oreillynet.com/cs/et2005/view/e_spkr/1848|title=Speaker Jeffrey P. Bezos|date=2005|publisher=[[O'Reilly Media]]|access-date=2020-05-21}}</ref><ref>{{Cite web |title=OpenSearch at A9 |url=https://www.allthingsdistributed.com/historical/archives/000542.html |date=15 Mar 2005 |access-date=9 Mar 2021 |archive-url=https://archive.is/m0mBB |archive-date=13 Mar 2021 |website=allthingsdistributed.com |last1=Werner |first1=Vogels}}</ref> Draft versions of OpenSearch 1.1 were released during September and December 2005. The OpenSearch specification is licensed by A9 under the [[Creative Commons]] Attribution-ShareAlike 2.5 License.<ref>{{cite web|url=https://github.com/dewitt/opensearch/blob/master/LICENSE.txt|title=LICENSE.txt|date=2018-05-31|access-date=2020-05-21}}</ref>
== Support ==
[[Web browser]]s that support OpenSearch include [[Safari (web browser)|Safari]],<ref>{{cite web
| url=https://developer.apple.com/library/archive/releasenotes/General/WhatsNewInSafari/Articles/Safari_8_0.html
| title=What's New in Safari 8.0
| date=2018-02-22
| publisher=[[Apple Inc.|Apple]]
| quote=In OS X, website developers can aid Safari in discovering searchable content by including an OpenSearch description document on their site, [...]
| access-date=2020-05-21}}</ref> [[Microsoft Edge]],<ref>{{Cite web
| url=https://support.microsoft.com/en-us/help/4028574/microsoft-edge-change-the-default-search-engine
| title=Change your default search engine
| date=2020-04-16
| publisher=[[Microsoft]]
| quote=However, you can change the default search engine in Microsoft Edge to any site that uses OpenSearch technology
| access-date=2020-05-21}}</ref> [[Firefox]]<ref>{{cite web
| url=https://developer.mozilla.org/en-US/docs/Archive/Add-ons/Supporting_search_suggestions_in_search_plugins
| title=Supporting search suggestions in search plugins
| date=2019-03-23
| publisher=[[Mozilla]]
| quote=Firefox supports search suggestions in OpenSearch plugins
| access-date=2020-05-21}}</ref> and [[Google Chrome]].<ref>{{cite web
| url=http://www.google.com/chrome/intl/en/webmasters-faq.html
| title=FAQ for web developers
| quote=By providing an OpenSearch description document (OSDD), you enable Google Chrome to include your site in the list of search engines in the browser.
| archive-url=https://web.archive.org/web/20120101182352/http://www.google.com/chrome/intl/en/webmasters-faq.html
| archive-date=2012-01-01
| url-status=dead
| access-date=2020-05-21}}</ref>
Mozilla have indicated that they will deprecate OpenSearch search addons in favour of WebExtentions search addons. This will not affect the ability to manually add an opensearch engine from a website<ref>{{cite web|url=https://blog.mozilla.org/addons/2019/10/15/search-engine-add-ons-to-be-removed-from-addons-mozilla-org/|title=Search Engine add-ons to be removed from addons.mozilla.org|date=2019-10-15|first=Caitlin|last=Neiman|publisher=Mozilla|access-date=2020-05-21}}</ref> As of December 5, 2019, search engine add-ons for Firefox that are powered by OpenSearch have been removed from Mozilla Add-ons.
== Design ==
[[File:Dewiki-suggesting-searchplugin.png|thumb|300px|Search suggestions in the [[German Wikipedia]]]]
OpenSearch consists of:
# '''OpenSearch Description files''': [[Extensible Markup Language|XML]] files that identify and describe a search engine.
# '''OpenSearch Query Syntax''': describe where to retrieve the search results
# '''OpenSearch [[RSS (file format)|RSS]]''' (in OpenSearch 1.0) or OpenSearch Response (in OpenSearch 1.1): format for providing open search results.
# '''OpenSearch [[Search aggregator|Aggregator]]s''': Sites that can display OpenSearch results.
# '''OpenSearch "Auto-discovery"''' to signal the presence of a search plugin link to the user and the link embedded in the header of HTML pages
OpenSearch Description Documents list search result responses for the given website/tool. Version 1.0 of the specification only allowed one response, in RSS format; however, version 1.1 provides support for multiple responses, which may be in any format. RSS and [[Atom (standard)|Atom]] are the only ones formally supported by OpenSearch aggregators, however other types, such as [[HyperText Markup Language|HTML]] are perfectly acceptable.
* Auto-discovery of an OpenSearch Description Document is available from both HTML and Atom or RSS feed documents via [[Link relations]] in the form of <code><atom:link rel="search" ... /></code> for Atom feeds<ref name=":0">{{Cite web|url = https://github.com/dewitt/opensearch/blob/master/opensearch-1-1-draft-6.md#autodiscovery-in-rssatom |title = Autodiscovery in RSS/Atom|date = 2019-12-08}}</ref> or <code><link rel="search" ... /></code> for RSS feeds<ref name=":0" /> and HTML documents.<ref>{{Cite web|url = https://github.com/dewitt/opensearch/blob/master/opensearch-1-1-draft-6.md#autodiscovery-in-htmlxhtml |title = Autodiscovery in HTML/XHTML|date = 2019-12-08}}</ref>
* OpenSearch Description Document must be placed on a web server of the same domain.<ref>{{cite web
| url=https://github.com/dewitt/opensearch/blob/master/mediawiki/Documentation/Developer%20how%20to%20guide.wiki
| title=How to return OpenSearch results from your search engine
| work=Developer how to guide.wiki
| date=2018-04-14
| access-date=2020-05-21}}</ref>
* OpenSearch Description Documents must be served with the <code>application/opensearchdescription+xml</code> [[Internet media type]].<ref>{{Cite web|url = https://github.com/dewitt/opensearch/blob/master/opensearch-1-1-draft-6.md#mime-type-applicationopensearchdescriptionxml|title = MIME type application/opensearchdescription+xml|date = 2019-12-08}}</ref>
==Alternatives==
Mozilla Firefox offers a bookmark keyword feature<ref>https://support.mozilla.org/en-US/kb/bookmarks-firefox#w_how-to-use-keywords-with-bookmarks</ref> where an occurrence of {{Var|%s}} in the bookmark URI gets replaced with the terms typed in the address bar following the initial keyword.
* [[Sherlock (software)]]<ref>https://wiki.developer.mozilla.org/en-US/docs/Web/API/Window/sidebar/Adding_search_engines_from_Web_pages$revision/1525363#Installing_Sherlock_plugins</ref>
== See also ==
* [[Representational State Transfer]] (REST)
* [[GraphQL]]
* [[OpenURL]]
* [[Search/Retrieve via URL]] (SRU)
* [[Z39.50]]
== References ==
{{reflist}}
==External links==
* {{official website|https://github.com/dewitt/opensearch}}, including specifications
* [https://mycroftproject.com/ Mycroft Project] – a collection of OpenSearch installers for Firefox
{{Internet search}}
{{web browsers}}
[[Category:Internet search engines]]
[[Category:Web syndication formats]]
[[Category:XML]]
[[Category:Open formats]]
[[Category:2005 software]]
