XMLSIE validation
As XMLSIE is defined by an XML-schema (XSD) there is virtually an unlimited number of softwares that can validate the document structure. XSD will however not validate the integrity of the actual content, for instance the internal references between objects within XMLSIE, such as the existence of an account referenced to from a ledger entry.
A tool to do handle this has been developed and is available as source code and deployed service: