There is a handy VCF To XML Converter available with which you can easily convert your contacts in vCard format (.vcf) as a specially formatted XML file should you need that. But you can probably do it also with some spreadsheet editors that support VCF format and usually can also export data to XML format.
Convert vCard contacts to XML document.
We have found one software suitable in our database for this conversion.
Microsoft Windows software - convert vcf to xml on Windows
A simple converter program
Convert from vcf 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.