A fast, scalable and extensible HTTP/1.1 compliant caching proxy server
Traffic Server is an extremely high performance Web proxy-caching server, and has a robust plugin API that allows you to modify and extend its behavior and capabilities.
Traffic Server is fast. It was designed from the start as a multi-threaded event driven server, and thus scales very well on modern multi-core servers. With a quad core 1.86GHz processor, it can do more than 30,000 requests/second for certain traffic patterns. In contrast, some of the other caching proxy servers we've used max out at around 8,000 requests/second using the same hardware.
It's extensible. It has native support for dynamically loading shared objects that can interact with the core engine. Yahoo! has internal plugins that remap URLs; route requests to different services based on cookies; allow caching of oAuth authenticated requests; and modify behaviors based on Cache-Control header extensions. We've replaced the default memory cache with a plugin. It's even possible to write plugins to handle other protocols like FTP, SMTP, SOCKS, RTSP; or to modify the response body. There is documentation for the plugin APIs, and sample plugin code available today.