Traffic Server is a high-performance building block for cloud services. Its more than just a caching proxy server; it also has support for plugins to build large scale web applications. Key features: Caching - Improve your response time, while reducing server load and bandwidth needs by caching and reusing frequently-requested web pages, images, and web service calls. Proxying - Easily add keep-alive, filter or anonymize content requests, or add load balancing by adding a proxy layer. Fast - Scales well on modern SMP hardware, handling 10s of thousands of requests per second. Extensible - APIs to write your own plug-ins to do anything from modifying HTTP headers to handling ESI requests to writing your own cache algorithm. Proven - Handling over 400TB a day at Yahoo! both as forward and reverse proxies, Apache Traffic Server is battle hardened.