Where to download the latest XProc RNG schemas?

Hello,

I found a discussion on this forum (Fri, 05 Feb 2010) about an duplicate
attribute "use-when" error when validating a pipeline. I ran into the same
error when doing a validating parse of a pipeline in an XProc engine I am
developing right now.

In my engine I use Jing 20091111 with xproc.rng and steps.rng files I picked
up from an Oxygen (version11?) installation. I patched these schema's (more
or less) to fix the "use-when" error, so I can proceed with the cases from
the XProc test suite for now.

Being new to this forum and to the XProc world, I wonder if there is a
central place where I can download "the official" schema's from.
-- 
Best regards,
Rijk Ravestein