Concurrency doesn't have to mean threading. I've used greenlet-based coroutines (http://pypi.python.org/pypi/greenlet http://pypi.python.org/pypi/greenlet) for

Concurrency doesn't have to mean threading. I've used greenlet-based coroutines (http://pypi.python.org/pypi/greenlet http://pypi.python.org/pypi/greenlet) for concurrency in large projects. They work with the GIL, and I find it easier to write correct coroutine-based programs.