Fantastic... Christian worked hard on Stackless and I think it`s a great feature. On Pypy it would be easier to maintain and add functionality, unfortunately, I struggle on Stackless internals and it`s low level C gimmicks so I can't help on it. It would be great to have something like a good framework in the future to make it`s adoption easier. We have the Stackless Examples project to address this initial learning curve thing. http://code.google.com/p/stacklessexamples/