Extensible Markup Language, a simple and powerful standard for representing structured data. It is a markup language that defines a set of rules for encoding documents in a format which is both human readable and machine readable. It is a flexible language for creating common information formats and sharing both the format and content of data over the Internet and elsewhere. XML is a formatting language recommended by the World Wide Web Consortium (W3C).
A proprietary spreadsheet format, the native format of the popular Microsoft Excel spreadsheet package. Older versions use .xls files, while more recent ones use the XML-based .xlsx variant.
An XML-based language (Web Services Description Language) used to describe the services a business offers and to provide a way for individuals and other businesses to access those services electronically.
Source: US OD