So, from what I can tell, Pluton : C/State-Threads :: Twisted : Python/select. It's a hybrid evented/threaded framework using cooperative thread scheduling, but it hides the thread scheduling in its API to make programming feel even more natural.<p>There are a lot of random projects that chased this idea; maybe someone here can list a couple? I'm just fascinated that Yahoo fielded major apps built on this one. Neat!