Dudle - Dudle is an online scheduling application, which is free and open source.
MINDBODY - Find and book fitness and beauty classes near you.
FullCalendar - FullCalendar is an open-source JavaScript event calendar.
Kajabi - Kajabi is the only Knowledge Commerce platform today with everything you need to market, sell, and deliver your knowledge online.
Framadate - Make your polls
Tendenci - Tendenci - The Open Source AMS is a cloud-based all-in-one management SaaS solution for Non-profits and Associations.