Sysv_ipc gives Python programs access to System V semaphores, shared memory 
and message queues. Most (all?) Unixes (including OS X) support System V IPC. 
Windows+Cygwin 1.7 might also work. 

Sample code is included.

sysv_ipc is free software (free as in speech and free as in beer) released
under a 3-clause BSD license. Complete licensing information is available in 
the LICENSE file.

You might also be interested in the similar POSIX IPC module at:
http://semanchuk.com/philip/posix_ipc/