Improving performance with Stackless Python

I don't know about gevent, but stackless will work with any libraries in the same way CPython does, which makes sense given it's just a fork. Native extensions obviously won't benefit from stackless but still work with it.

Exceptions and threads don't mix well however, so using Stackless' microthreads with code that relies on exceptions will likely lead to slowdown, so there are a few things to be aware of.