The Extensible Markup Language (XML) is a markup language that may be used to create organized electronic texts. Extensible Markup Language (XML) is a computer language used by data exchange services (such as blog feeds) to transfer data across systems that are otherwise incompatible. It is based on SGML (standard generalized markup language), an international standard for electronic texts, and is usable by both people and machines. XML is the foundation for several other languages, including RSS and XHTML.