* Thread-safe. * Six times faster than Boost.Signals. * Separate access specification for connection and firing the event. * Events can be virtual and pure virtual (can be used in interfaces). * Event chaining. * Simple delegate binding. * Non-intrusive connection tracking and automatic disconnecting.

* 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, fast timer management, time jump detection and correction, and ease-of-use. * It can be used as a libevent replacement using its emulation API or directly embedded into your programs without the need for complex configuration support. * Libev supports select, poll, the Linux-specific epoll, the BSD-specific kqueue and the Solaris-specific event port mechanisms for file descriptor events (ev_io), the Linux inotify interface (for ev_stat), Linux eventfd/signalfd (for faster and cleaner inter-thread wakeup (ev_async)/signal handling (ev_signal)) relative timers (ev_timer), absolute timers with customised rescheduling (ev_periodic), synchronous signals (ev_signal), process status change events (ev_child), and event watchers dealing with the event loop mechanism itself (ev_idle, ev_embed, ev_prepare and ev_check watchers) as well as file watchers (ev_stat) and even limited support for fork events (ev_fork).