libevent: libevent - an event notification library
libevent:
libevent: The libevent API provides a mechanism to execute a callback function
libevent: when a specific event occurs on a file descriptor or after a timeout
libevent: has been reached. Furthermore, libevent also support callbacks due to
libevent: signals or regular timeouts.
libevent: 
libevent: libevent is meant to replace the event loop found in event driven
libevent: network servers. An application just needs to call event_dispatch()
libevent: and then add or remove events dynamically without having to change the
libevent: event loop.