GNU Health - GNU Health is a Free/Libre project for health practitioners, health institutions and governments.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
OpenMRS - OpenMRS is a community-developed, open source, enterprise electronic medical record system platform.
Splash - Anyone can create a Splash event, whether you're a company hosting a single event or an individual hosting a personal event like a birthday or wedding. Get Started for Free. Text goes here. X. Full Event Program.
drchrono - An EHR built for your specialty:
Eventzilla - Eventzilla lets you sell tickets online and manage attendees from one integrated application.