Just because Java was once aimed at a set-top box OS that didn't
support multiple address spaces, and just because process creation in
Windows used to be slow as a dog, doesn't mean that multiple processes
(with judicious use of IPC) aren't a much better approach to writing
apps for multi-CPU boxes than threads.
Just Say No to the combined evils of locking, deadlocks, lock granularity, livelocks, nondeterminism and race conditions.
-- Guido van Rossum, http://mail.python.org/pipermail/python-3000/2007-May/007414.html