uthreads is a microthreading library layered on top of Twisted Python. It is similar to DeferredGenerator, but uses features only present in Python 2.5 to make the microthreaded code much more natural to read and write. See the MotivatingExample for an idea of how uthreads can be useful.
uthreads aims to be a compact, efficient, and easy-to-use microthreading platform, allowing users to concentrate on writing their applications in a natural fashion while retaining all of the benefits of microthreaded programming. Applications can easily intermix twisted code with microthreaded code, as the structure of the application dictates.