Most "active" coroutine library project?

[Phillip B Oldham]

I've been taking a look at the multitude of coroutine libraries
available for Python, but from the looks of the projects they all seem
to be rather "quiet". I'd like to pick one up to use on a current
project but can't deduce which is the most popular/has the largest
community.

Libraries I looked at include: cogen, weightless, eventlet and
circuits (which isn't exactly coroutine-based but it's event-driven
model was intriguing).

Firstly, are there any others I've missed? And what would the
consensus be on the which has the most active community behind it?