AnyEvent provides a uniform interface to various event loops. This allows module
authors to use event loop functionality without forcing module users to use a
specific event loop implementation (since more than one event loop cannot
coexist peacefully).

The interface itself is vaguely similar, but not identical to the Event module.

During the first call of any watcher-creation method, the module tries to detect
the currently loaded event loop by probing whether one of the following modules
is already loaded: EV, AnyEvent::Loop, Event, Glib, Tk, Event::Lib, Qt, POE. The
first one found is used. If none are detected, the module tries to load the
first four modules in the order given; but note that if EV is not available, the
pure-perl AnyEvent::Loop should always work, so the other two are not normally
tried.