RDF query

Hi everyone,
   
     I am quite new to this RDF. I am currently working on a project which involves RDF. I wanted to know if there is any software or query language which can query RDF/XML files in XML.
     What I mean here is the syntactic constructs of the query language should be in XML,i.e, I should be able to write the queries in XML.
      Hope to hear from you guys soon.

  Thank you,

Regards.