I would like to use fcl-xml, as I have to generate and process xml files. Is there a document describing all of its classes, with the properties and methods available? I found only one wiki (https://wiki.freepascal.org/XML_Tutorial) certainly useful, but not exhaustive. Thanks.
I know this is not exactly what you asked for, but...
None of the fcl-xml units are documented in the official fcl docs. The LazUtils package has documentation for the UTF-8 variants implemented for Lazarus. I don't know that I'd use the word "exhaustive", but there are help topics.
Hope that helps.