[XeTeX] XeTeX, font protrusion, and the microtype package

[Jonathan Kew]

On 4/10/12 09:06, Philip TAYLOR wrote:
> Could anyone please tell me the XeTeX primitives into which
> the Microtype package hooks in order to enable font protrusion ?
> The output of "TeXdoc XeTeX" makes no reference to any such
> primitives.  I would like to be able to make use of whatever
> microtypographic features XeTeX offers, but of course being
> a non-LaTeX user pre-packaged solutions such as the Microtype
> package are of no direct use to me.

The clues you're looking for can be found in the archives of this list: 
see http://tug.org/pipermail/xetex/2010-May/016465.html.

JK