Framadate - Make your polls
Dudle - Dudle is an online scheduling application, which is free and open source.
Nuages - Nuages is a collaborative meeting poll system..
Doodle - Make meetings happen. With Doodle, scheduling becomes quick and easy.
WhenIsGood - Plan the time to have your meeting or event by co-ordinating availability with all the particpants using this fuss-free online tool.
FullCalendar - FullCalendar is an open-source JavaScript event calendar.