It uses the multiprocessing package, which is new in Python 2.6. From the docs: The multiprocessing package offers both local and remote concurrency, effective

It uses the multiprocessing package, which is new in Python 2.6. From the docs: The multiprocessing package offers both local and remote concurrency, effectively side-stepping the Global Interpreter Lock by using subprocesses instead of threads. http://docs.python.org/library/multiprocessing.html http://docs.python.org/library/multiprocessing.html