XSLT, which stands for Extensible Stylesheet Language Transformations, is a declarative, XML-based language used for the transformation of XML documents into other XML documents. The input document is used to create a new output document using the data in the input document along with the rules described in the XSLT document. The style of programming is that of a functional language with string matching, rather than a procedural language. Learning to create XSLT 'programs' is not difficult, but changing to the functional programming paradigm for those accustomed to procedural languages does require a different approach to problem solving.
XML Extensions creates (exports) or consumes (imports) only documents which 'match' the hierarchical structure of a COBOL record area. When the external requirements for an XML document do not achieve this match, XSLT is used. For example, SOAP web services require the creation of a very complicated XML document, the WSDL, to describe the web service. Xcentrisity BIS uses XSLT to create the WSDL from a COBOL data description - matching the relatively simple data layout to the complex WSDL XML document.