I am having a project on faculty, and my PhD. Professor wants me to use only XML database, not MySQL database. So my question is how can I use an XML database on xampp, and which xml database should I use?
You can start from here: http://en.wikipedia.org/wiki/XML_database
'xampp' is just a bundle of preconfigured servers (mysql, apache + php). There is no relation between 'xampp' and usage of databases.
Update: If you use php for your application backend and choose to use BaseX for database then check http://docs.basex.org/wiki/PHP_Example