Lingerd is a daemon (service) designed to take over the job of properly closing network connections from an http server like Apache.

Because of some technical complications in the way TCP/IP and HTTP work, each Apache process currently wastes a lot of time "lingering" on client connections, after the page has been generated and sent. Lingerd takes over this job, leaving the Apache process immediately free to handle a new connection. As a result, Lingerd makes it possible to serve the same load using considerably fewer Apache processes.

Warning: will only work (properly) if KeepAlive is disabled.