Python Asynchronous Frameworks are plentiful in the Python Community. There is Twisted, gevent, Tornado, asynccore and now with Python 3.4, asyncio. circuits is not yet another Asynchronous Framework (although it does support Async I/O) but a strong well defined Component Architecture for building complex software with changing requirements. If you have ever developed with Zope or Kamaelia you will be familiar with the "Component" concept. circuits offers a unique perspective on Component Architectures and offers a novel way to design, implement and deploy complex software.