Nuages - Nuages is a collaborative meeting poll system..
Framadate - Make your polls
Dudle - Dudle is an online scheduling application, which is free and open source.
FullCalendar - FullCalendar is an open-source JavaScript event calendar.
WhenIsGood - Plan the time to have your meeting or event by co-ordinating availability with all the particpants using this fuss-free online tool.
Xoyondo - Xoyondo makes it easy to find a date for your event that works for everybody. You can also create polls and conduct surveys. Xoyondo is free. No registration required.