DirectMemory is an off-heap cache implementation (a la BigMemory) to enable in-memory serialization of a large number of Java objects without affecting JVM garbage collection performance. Although serialization makes things slower, put/get operations are well in the sub-millisecond range, which is pretty acceptable in every usage scenario. DirectMemory implements cache eviction based on a simple LRU (Less Recently Used) algorithm and on item expiration.
The Apache Traffic Server (TS or ATS) is a modular, high-performance reverse proxy server, generally comparable to Squid. It was created by Inktomi, and distributed as a commercial product called the Inktomi Traffic Server, before Inktomi was acquired by Yahoo!. Traffic Server has been actively used inside of Yahoo for over 4 years, serving billions of requests every day. As of fall 2009, Traffic Server is an Open Source project, and in April 2010 the Apache Traffic Server was promoted to a top-level project of the ASF.