On Dec 18, 2005, at 6:57 AM, Gendag wrote:
> I've started to learn Ruby  two days ago and it's fantastic! :-)
> I need I help, i need a lib to validate a XML file and to create
> a DOM tree.

I highly recommend REXML for creating the DOM tree and working with  
the XML. But I don't believe it does DTD/Schema validation.

Thankfully, there seem to be lots of other programs and web services  
that do this bit. Although it would be nice to wrap it all up into  
one nice little package, how about doing both with separate pieces?

For example, start here http://www.cogsci.ed.ac.uk/~richard/xml- 
check.html
If you don't choose to use that web service, perhaps the software it  
links to (or the software that the pages it links to themselves link  
to) will help. Remember that Ruby can invoke programs from the shell/ 
command line, and retrieve the results.