upgrading to newest docbook5 (both validation and conversion)

Hi,

I have the opportunity to restage a production machine for DocBook5 production. I convert from LaTeX to DocBook5 and then use the DocBook stylesheets to generate various flavors of HTML. 

 

So I need to restage using the latest downloads for validation and conversion.

 

I see that the newest (ns) stylesheets are 1.76, which is great and I've got them.  But I can't figure out which relaxng spec to download: 5.0? 5.0b6? This is going to be a production environment and needs to include mathml if possible.

 

thanks,

--Tim Arnold