FullCalendar - FullCalendar is an open-source JavaScript event calendar.
Doodle - Make meetings happen. With Doodle, scheduling becomes quick and easy.
Letsfind - Letsfind is a fast, easy-to-use, ad-free way to create online (meeting) polls.
When2Meet - When2meet helps you find the best time for a group to get together. It is a free survey tool that is quick and easy to use.
FreeBu - Smart free/busy calendar sharing and meeting organizer.
Let's Meet On - A super simple way for groups to find a date and time when everyone is available.