Thank you for the information!

> I donít know anything about memcache. But will look into it.
> Suggestions are welcome.

I've never used it too. But I think, we would need four functions in the PHP API:
1) pre-parse XML data and store it into memcache
2) pre-compile XSLT stylesheet and store it into memcache
3) load pre-parsed XML data from memcache and use it as source for transformation
4) use pre-compiled stylesheet from memcache and use it for transformation

> Is it possible for you to send me your stylesheet(s) and source
> documents so that I can analyse the performance at my end.

Thanks for that offering! I will do that as soon as I've set up my virtual machine. Then I will be sure about the "real" performance which could be different from that on my own computer.

Best regards