• It is easy to make mistakes writing XSLT
• Remember it is an XML application so always check your stylesheet is legal XML
• Saxon and MSXML error messages are often cryptic
• xsl:message can insert debug statements
• Inserting debug elements can help
• Most XSLT editors crash under any significant XSLT transformation
• Microsoft have a good .NET environment
• Some Editors:
  • Oxygen XSLT Debugger: $64 academic licence
  • Axizon Tiger writes your XSLT for you given input and output XML
  • Altova XML Spy XSLT Debugger: 30-day free download
  • Sonic Stylus Studio: $99
  • KsXML (Free!)

Good ones all cost money and some are expensive!

Most fail on my complex XSLT transformations