Seeking source code that computes MM2 energy

[ngo : at : tammy.harvard.edu]

 I am looking for source code that computes the MM2 energy.  It does
 not need to be a complete program, as I just want to use it to help me
 answer some detailed questions about what interactions are and are not
 included.  However, for this reason the implementation must be true to
 the "official" MM2 definition.
 I would prefer to get the code from somewhere on the net, and I do not
 want to pay for it.  (Maximum tolerable price is around $50.)
 Any help would be appreciated.  Please send replies via email, and if
 this question turns out not to have been a FAQ, I will summarize to
 this list.  Thanks,
 --Tom Ngo
   ngo : at : tammy.harvard.edu