A general-purpose markup language is a markup language that is used for more than one purpose or situation. Other, more specialized domain-specific markup languages are often based upon these languages. For example, HTML 4.1 and earlier are domain-specific markup languages (for webpages), and are based on the syntax of SGML, which is a general-purpose markup language. List Notable general-purpose markup languages include: ASN.1 (Abstract Syntax Notation One) EBML LML - general-purpose markup language for expressing markdown, variables, and expressions for machine-readable and executable legal documentation GML - the predecessor of SGML SGML - a predecessor of XML XML - a stripped-down form of SGML YAML GLML - General-purpose Legal Markup Language See also Comparison of document markup languages General-purpose language General-purpose modeling language General-purpose programming language S-expression Data serialization formats