Acronym: eXtensible Markup Language
From their homepage:
- Extensible Markup Language (XML) is a simple, very flexible text format derived from SGML (ISO 8879). Originally designed to meet the challenges of large-scale electronic publishing, XML is also playing an increasingly important role in the exchange of a wide variety of data on the Web and elsewhere.
XML is a meta language for creating markup languages. It is a successor to SGML. It can be described as a metalanguage defining the way to format data for efficient transmission and processing. The XML schema explain the publisher's structure by defining shared mark-up vocabularies.
XML is an important move towards developing efficient resource discovery on the Web, although it does not completely solve the problem. XML is important because it facilitates access to metadata and more, allowing a publisher to address the meaning of their content.