• Option to ignore the order of child elements
• Can generate diff output as a diffgram (XML Diff Language, Delta Update Language or XUpdate)
• Can combine an input with a diffgram to produce a merged output
• Provides a Java API
• Available under a no-charge open source or non-commercial license

List of known implementations that provide the features we require:

• developer.berlios.de/projects/tdm/ (a possibility - numbers nodes)
• SourceForge DiffXML (looks good - names nodes)

Those that don't:

• Microsoft (.Net only)
• Sun's diffmk (perl)
• http://www.cs.wisc.edu/~yuanwang/xdiff.html (doesn't generate diffgram)
• DeltaXML (commercial, ordered children)
• DecisionSoft xmldiff (doesn't generate diffgram)
• VMGuys VMtools (doesn't generate diffgram)
• LogiLab XmlDiff (python)
• http://search.cpan.org/dist/XML-SemanticDiff/SemanticDiff.pm (Perl)

Unknown

• IBM Alphaworks XmlTreeDiff^?
• [[http://nwalsh.com/java/diffmk/][NW (of Sun)'s diffmk]
• IBM Alphaworks (gui tool?)
• http://www.dommitt.com/v2.0pages/mainpage-index.html (wehbsite offline)
• http://www.xmldb.org/xupdate/ (dead project?)
• http://people.via.ecp.fr/~remi/soft/xml/xmldiff/xmldiff_en.php3
• http://www.smb-tec.com/treediff/treediff.jar

References

• http://citeseer.ist.psu.edu/449452.html
• http://www.xmldb.org/xupdate/xupdate-wd.html#N19b1de
• http://trieloff.net/docbook/archive/000439.html

Formats

• XDL - numbered
• DUL - named and numbered
• XUpdate - named and numbered