PluXml is a blog/CMS storing data in XML and not in a SQL database.
Plugins and themes should respectively be installed in the following folders:
To restore your blog, you should keep a copy of the folder
/var/www/pluxml/data. It is recommended to do this backup before any upgrade.
PluXml : https://www.pluxml.org/
Documentation : https://wiki.pluxml.org/
Forum : https://forum.pluxml.org/
Found errors? Think you can improve this documentation? Simply click the Edit link at the top of the page, and then the icon on Github to suggest changes.