Eventlet Looks Familiar

Linden labs (Second Life developers) are using a library named Eventlet to abstract non-blocking network IO behind co-routines.

I'm glad I've seen this, as Eventlet uses similar techniques to fibra, and validates my approach. In fact, this quote from the Eventlet wiki, applies equally to fibra:

Eventlet began life as Donovan Preston was talking to Bob Ippolito about coroutine-based non-blocking networking frameworks in Python. Most non-blocking frameworks require you to run the "main loop" in order to perform all network operations, but Donovan wondered if a library written using a trampolining style could get away with transparently running the main loop any time i/o was required, stopping the main loop once no more i/o was scheduled.