Validating XML against XSD

Hi Folks,
     I got into a pitch hole when during the development stage of my
project when I came across a scenario where in I had to validate an
XML against and XSD.After a hell lot of googling, I couldnt really
manage to find a solution for the same.At last I found a commad line
utility called xmlstartlet whcih i integrated into my project and
generated a helper out of it to use its functionality under the rails
framework.The way wokred around it could be found right our here on my

But i find find this as an ultimate solution when considering the time
performance of the projetc as every request for the XSD based
validation is routed to some external utility…!..Can anybody tell
me if therez any better work around for this issue…and any other
ruby based library or plugin which can help me out with this???