On 16/06/2010 14:00, Martin Schröder wrote:
> Just a reminder: pdftex/luatex does random numbers since 1.30.0
> (released 2005-08-01). Porting that code to XeTeX would probably be
> trivial.

A PRNG is not actually too hard (I already have some code to do this). 
At present, we only require a single post-e-TeX primitive (\pdfstrcmp), 
and I think we'd like to keep it that way if possible. As I can write a 
PRNG in TeX, I think for the moment that will be the way to do things.
Joseph Wright