Castor EDC - Castor offers you a user-friendly and fully featured application for electronic data collection.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
GNU Health - GNU Health is a Free/Libre project for health practitioners, health institutions and governments.
Cvent - Cvent's event management software provides event planners with a complete solution to increase event attendance and decrease event costs.
OpenClinica - OpenClinica is an open source clinical trials software.
EventMobi - EventMobi is an interactive mobile event app, audience response and engagement platform for conferences and trade shows.