Internal Program Version: libev  4.24

An event loop that is loosely modeled after libevent. Features
include child/PID watchers, periodic timers based on wallclock
(absolute) time (in addition to timers using relative timeouts), as
well as epoll/kqueue/event ports/inotify/eventfd/signalfd support,
timer management, time jump detection and correction.

http://software.schmorp.de/pkg/libev.html