Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online.XSL Transformations (XSLT) is a declarative XML-based language used for the transformation of XML documents into other XML documents. The original document is not changed; rather, a new document is created based on the content of an existing one. The new document may be serialized (output) by the processor in standard XML syntax or in another format, such as HTML or plain text. XSLT is often used to convert XML data into HTML or XHTML documents for display as a web page: the transformation may happen dynamically either on the client or on the server, or it may be done as part of the publishing process. It is also used to create output for printing or direct video display, typically by transforming the original XML into XSL Formatting Objects to create formatted output which can then be converted to a variety of formats, a few of which are PDF, PostScript,AWT and PNG. XSLT is also used to translate XML messages between different XML schemas, or to make changes to documents within the scope of a single schema, for example by removing the parts of a message that are not needed.