# XML

> markup language by the W3C for encoding of data

**Wikidata**: [Q2115](https://www.wikidata.org/wiki/Q2115)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/XML)  
**Source**: https://4ort.xyz/entity/xml

## Summary
XML is a markup language developed by the World Wide Web Consortium (W3C) for encoding data, designed to be self-descriptive and platform-independent.

## Key Facts
- Developed by the World Wide Web Consortium (W3C) as a markup language for encoding data
- Inception: 1998 (first W3C Recommendation published February 10, 1998)
- Based on Standard Generalized Markup Language (SGML) but simplified for web use
- File extension: .xml
- Media types: application/xml and text/xml
- Authors: Michael Sperberg-McQueen, Jean Paoli, and Tim Bray
- Standards body: World Wide Web Consortium
- Two main versions: XML 1.0 (published November 26, 2008) and XML 1.1 (published August 16, 2006)

## FAQs
### Q: What is XML used for?
A: XML is used for encoding data in a self-descriptive format that can be processed by computers and humans alike, enabling data exchange between different systems.

### Q: What is the difference between XML and HTML?
A: XML is a markup language for data encoding, while HTML is a markup language for web pages. XML is more flexible and can represent any kind of data structure.

### Q: What are some common applications of XML?
A: XML is used in various applications including the Semantic Web, Extensible HyperText Markup Language (XHTML), OpenDocument format, and Office Open XML.

## Why It Matters
XML has revolutionized how data is structured and exchanged across different systems and platforms. Before XML, data formats were often proprietary and incompatible, making it difficult to share information between different software applications. XML provides a standardized way to represent data that is both human-readable and machine-processable, enabling interoperability between different systems and platforms. Its self-descriptive nature allows developers to create custom tags for specific data elements, making it highly flexible for various applications. XML has become the de facto standard for data exchange in many industries, including web services, e-commerce, and document management systems.

## Notable For
- First introduced as a W3C Recommendation in 1998, providing a standardized way to encode data
- Based on SGML but simplified for web use, making it more accessible than its predecessor
- Created to be platform-independent and extensible, allowing users to define their own tags
- Has become the foundation for many other technologies like XHTML, RSS, and SOAP
- Supports namespaces to avoid naming conflicts when combining different XML vocabularies

## Body
### History and Development
XML was developed by the World Wide Web Consortium (W3C) as a markup language for encoding data. The first W3C Recommendation was published on February 10, 1998. The development was led by Michael Sperberg-McQueen, Jean Paoli, and Tim Bray. XML is based on Standard Generalized Markup Language (SGML) but simplified to be easier to implement on the web.

### Technical Specifications
XML uses a syntax that allows for self-descriptive tags. The language defines rules for creating elements, attributes, and entities. It supports namespaces to prevent naming conflicts when combining different XML vocabularies. The file extension for XML files is .xml, and the media types are application/xml and text/xml.

### Versions and Evolution
XML has evolved through several versions. The first major version was XML 1.0, published as a W3C Recommendation on November 26, 2008. A second version, XML 1.1, was published on August 16, 2006. Both versions are still in use today.

### Usage and Applications
XML is widely used in various applications including:
- The Semantic Web for representing structured data
- Extensible HyperText Markup Language (XHTML) for web pages
- OpenDocument format for office documents
- Office Open XML for Microsoft Office documents
- Web services like SOAP and REST

### Implementation and Tools
Many tools and libraries have been developed to work with XML. These include parsers, validators, and transformation tools. The XML namespace is used to manage namespaces in XML documents. XML Schema is used to define the structure and constraints of XML documents.

```json
{
  "@context": "https://schema.org",
  "@type": "Thing",
  "name": "XML",
  "description": "A markup language developed by the World Wide Web Consortium (W3C) for encoding data",
  "url": "http://www.w3.org/XML",
  "sameAs": ["https://www.wikidata.org/wiki/Q328", "https://en.wikipedia.org/wiki/XML"],
  "additionalType": "markup language"
}

## References

1. [Source](http://www.digitalpreservation.gov/formats/fdd/fdd000075.shtml)
2. [Source](https://www.w3.org/TR/1998/REC-xml-19980210)
3. Freebase Data Dumps. 2013
4. [Source](https://www.file-extension.info/format/xml)
5. [Newest 'xml' Questions - Stack Overflow](https://stackoverflow.com/questions/tagged/xml)
6. YSO-Wikidata mapping project
7. BabelNet
8. [XML | HTML & CSS Wiki | Fandom](https://htmlcss.fandom.com/wiki/XML)
9. FactGrid
10. National Library of Israel
11. [XML: Extensible Markup Language | MDN](https://developer.mozilla.org/en-US/docs/Web/XML)
12. KBpedia
13. [OpenAlex](https://docs.openalex.org/download-snapshot/snapshot-data-format)
14. Wikibase TDKIV