I know of 2; one which Ross Inglis wrote and uploaded to Compuserve
(including source in C for those who would want to compile it on their
workstation or Mac, or ...), and another from an unknown-to-me source.
What I did for my associates was to take Ross' simulator and put a
front-end on it so that the results could be made available via email,
using no more than the elm filter. Procmail or similar could do the
same thing. I'm not offering to make mine available, however, as the
machine it's running on is one which has usage limits before it starts
costing $$, and a -few- people using it doesn't push me over my limit.
But I'd be happy to help someone do the same thing for their system
if they've got access to similar tools--it's pretty simple under unix.