1Tornado is an open source version of the scalable, non-blocking web server and 2tools that power FriendFeed. The FriendFeed application is written using a web 3framework that looks a bit like web.py or Google's webapp, but with additional 4tools and optimizations to take advantage of the underlying non-blocking 5infrastructure. 6 7The framework is distinct from most mainstream web server frameworks (and 8certainly most Python frameworks) because it is non-blocking and reasonably 9fast. Because it is non-blocking and uses epoll or kqueue, it can handle 10thousands of simultaneous standing connections, which means it is ideal for 11real-time web services. We built the web server specifically to handle 12FriendFeed's real-time features - every active user of FriendFeed maintains an 13open connection to the FriendFeed servers. 14