XSLT stylesheets may be used to provide an alternative and more legible syntax for XML documents. However, such transformations are not reversible since no tool exists to automatically parse the alternative syntax back into XML.

We present XSugar, which is a reversible stylesheet language for XML. An XSugar specification is built around a context-free grammar for the alternative syntax and gives a template-based translation into XML. The XSugar tool can then provide three services:

• a static guarantee that all XML documents generated from alternative syntax are valid according to a given XML schema;
• a translation from alternative syntax into XML; /and/
• a reverse translation from XML into alternative syntax (provided certain injectivity requirements are satisfied).