I want to transform a largeish number of XML instances (a few
thousand) at a time, and so want to avoid repeatedly recompiling the
XSLT script.  I suppose an alternative would be to create a Template,
and repeatedly create a Transformer from that.  That would be quite
cheap, yes?

I've just uploaded a new version of Kernow (in beta so please report
any issues) - in this latest version directory transforms are
multithreaded to take advantage of multicore processors.

For Norman: Kernow is a graphical front / high level API for Saxon
that takes care of things like compiling the stylesheet.  You can run
directory transforms either using the GUI or through its API, eg:

Kernow kernow = new Kernow();
kernow.runDirectoryTransform(inputDir, XSLT, outputDir);

That's the minimum, there are various other methods to set parameters
and configuration options.

cheers
andrew

--
http://andrewjwelch.com