If you feed in xml/xhtml into DomToGroovy which looks something like: <a href="http://groovy.codehaus.org">Groovy</a> It outputs something like: a(href:'http://groovy.codehaus.org') ["Groovy"] but MarkupBuilder seems to currently only like: a(href:'http://groovy.codehaus.org', "Groovy") I think we should change DomToGroovy to output the currently supported builder notation. There is a DomToGroovyTest.groovy file which checks that the currently incompatible behaviour is in place. Perhaps it should be modified to always pass its output back into MarkupBuilder and perhaps (with some XMLUnit magic) check that it produces what was fed in in the first place.