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JSON, (canonically pronounced ;〔(【引用サイトリンク】 date = 7 February 2009 )〕 sometimes JavaScript Object Notation), is an open standard format that uses human-readable text to transmit data objects consisting of attribute–value pairs. It is the primary data format used for asynchronous browser/server communication (AJAJ), largely replacing XML (used by AJAX). Although originally derived from the JavaScript scripting language, JSON is a language-independent data format. Code for parsing and generating JSON data is readily available in many programming languages. The JSON format was originally specified by Douglas Crockford. It is currently described by two competing standards, RFC 7159 and ECMA-404. The ECMA standard is minimal, describing only the allowed grammar syntax, whereas the RFC also provides some semantic and security considerations. The official Internet media type for JSON is application/json. The JSON filename extension is .json.==History== JSON grew out of a need for stateful, real-time server-to-browser communication without using browser plugins such as Flash or Java applets, which were the dominant method in the early 2000s. Douglas Crockford was the first to specify and popularize the JSON format.〔(Video: Douglas Crockford — The JSON Saga ), on Yahoo! Developer Network. In the video Crockford states: "I do not claim to have invented JSON ... What I did was I found it, I named it, I described how it was useful. ... So, the idea's been around there for a while. What I did was I gave it a specification, and a little Web site."〕 The acronym was coined at State Software, a company co-founded by Crockford, Chip Morningstar and Robert F. Napiltonia in April 2001 and funded by Tesla Ventures. The co-founders agreed to build a system that used standard browser capabilities and provided an abstraction layer for Web developers to create stateful Web applications that had a persistent duplex connection to a Web server by holding the two HTTP connections open and recycling them before standard browser time-outs if no further data were exchanged. The idea for the State Application Framework was developed by Morningstar at State Software.〔 (【引用サイトリンク】 date = n.d. ) 〕〔 〕 It was used in a project at Communities.com for Cartoon Network, which used a plug-in with a proprietary messaging format to manipulate DHTML elements (this system is also owned by 3DO). Upon discovery of early Ajax capabilities, digiGroups, Noosh, and others used frames to pass information into the user browsers' visual field without refreshing a Web application's visual context, realizing real-time rich Web applications using only the standard HTTP, HTML and JavaScript capabilities of Netscape 4.0.5+ and IE 5+. Crockford then found that JavaScript could be used as an object-based messaging format for such a system. The system was sold to Sun Microsystems, Amazon.com and EDS. The (JSON.org ) Web site was launched in 2002. In December 2005, Yahoo! began offering some of its Web services in JSON.〔 〕 Google started offering JSON feeds for its GData web protocol in December 2006.〔(【引用サイトリンク】title= Using JSON with Google Data APIs ) 〕 Although JSON was originally based on a non-strict subset of the JavaScript scripting language (specifically, Standard ECMA-262 3rd Edition—December 1999) and is commonly used with that language, it is a language-independent data format. Code for parsing and generating JSON data is readily available for a large variety of programming languages. JSON's Web site lists JSON libraries by language. Though JSON is commonly perceived as being a subset of JavaScript and ECMAScript, it allows some unescaped characters in strings that are illegal in JavaScript and ECMAScript strings.〔(【引用サイトリンク】JSON: The JavaScript subset that isn't. )〕 A typical mashup fetches JSON-format data from several different web servers using an Open API. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「json」の詳細全文を読む スポンサード リンク
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