Extensible Stylesheet Language(XSL):

Read About ☛ XSL-FO

In computing, the term Extensible Stylesheet Language (XSL) is used to refer to a family of languages used to transform and render XML documents.

Read About ☛ XSLT Programming Language:

XSL is a language for expressing style sheets. An XSL style sheet is, like with CSS, a file that describes how to display an XML document of a given type. XSL shares the functionality and is compatible with CSS2 (although it uses a different syntax).
It also adds:
A transformation language for XML documents: XSLT.
Read About ☛ XSLT Language:

Read About ☛ XSLT Role:

Read About ☛ Extensible Stylesheet Language Transformations(XSLT):