scene.spad line 3896 [edit on github]
This package provides support for XML files
writeVRML(content, filename) writes the element as VRML2. VRML2 is not xml but it has the same semantics and node names as X3D but a different syntax so it makes sense to create an XML structure and then format the output differently.
writeXml(content, filename) writes an xml element and all the elements below it to an xml file. This assumes that all elements, in a file, have a single root which is usually the case.