XML in a Nutshell, 3rd Edition

Chapter 24. XSLT Reference

Extensible Stylesheet Language Transformations (XSLT) is a functional programming language used to specify how an input XML document is converted into another text document—possibly, although not necessarily, another XML document. An XSLT processor reads both an input XML document and an XSLT stylesheet (which is itself an XML document because XSLT is an XML application) and produces a result tree as output. This result tree may then be serialized into a file or written onto a stream. Documents can be transformed using a standalone program or as part of a larger program that communicates with the XSLT processor through its API.