Yes, there are really advanced libs out there. I would advice you to look at irrXML and tinyXML. tinyXML reads instead of irrXML the whole document into memory and is able to write it back (when you modify it, for instance). irrXML is a bit easier to use in my oppinion and its very fast. It has been written by the guy who wrote the irrLicht engine. With LiteC you might be able to bind both into the engine (though I still prefer writing my own wrapper DLLs), with CScript you need a wrapper DLL to access the libs.

Amadeu, if you want to produce HTML pages with GS, you are free to. Use the file_* commands to assemble a HTML page. I saw this several times here e.g. for storing debugging infos, etc. Just have a look into the file_* commands and then generate your own HTML.