I just gave this a quick run. There aren't many options; however, it's very easy and quick to use. It can definitely suffice many use cases.
FullCalendar - FullCalendar is an open-source JavaScript event calendar.
Doodle - Make meetings happen. With Doodle, scheduling becomes quick and easy.
Let's Meet On - A super simple way for groups to find a date and time when everyone is available.
WhenAvailable - WhenAvailable is an excellent event management tool that allows scheduling the dinner party, book club meeting, and guys’ night out with simple and best ideas.
CozyCal - Online appointment scheduling
WhenIsGood - Plan the time to have your meeting or event by co-ordinating availability with all the particpants using this fuss-free online tool.