XSLTransformation.cs

var message = @"c:\message.xml";
var xslTransformation = @"c:\messagetransformation.xsl";

var xslDocument = new XslCompiledTransform();
xslDocument.Load(xslTransformation);
var stringWriter = new StringWriter();
var xmlWriter = new XmlTextWriter(stringWriter);
xslDocument.Transform(message, xmlWriter);
//Load the transformed output in a WPF WebBrowser control
webBrowser.NavigateToString(stringWriter.ToString());