== XSugar ==
The [http://www.brics.dk/xsugar XSugar] project has developed a 
notation for specifying a ''dual syntax'' for an [[XML|XML]] language.

An XSugar specification gives rise to the following tools:
* a translation from XML to non-XML syntax
* a translation from non-XML to XML syntax
* a check that these translations are reversible
* static validation of the generated XML documents