The Zen Differential was supposed to be a
movie directed by
Michael Mann and produced by
Kathryn Sommer. The screenplay was written by
John Lloyd Parry in 1996 and was based on the novel
Count Zero by
William Gibson.
This project used to be listed on
The Internet Movie Database under William Gibson, but isn't any longer. I can't find any up-to-date information on this, so the movie probably got canned. Too bad. You can still read the script, though, at:
http://www.8op.com/gibson/en/zendifferential.html