Should you need it, you can re-save ZARGO ARGO UML models (*.zargo) to basic XML using the Poseidon for UML program. Probably exports just some data as standard XML.
Convert ArgoUML model file to XML Metadata Interchange Format.
We found one software available in the database for this conversion.
Microsoft Windows software - convert zargo to xmi on Windows
A program for modelling in UML language
Convert from zargo file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.