GNU Health - GNU Health is a Free/Libre project for health practitioners, health institutions and governments.
OpenClinica - OpenClinica is an open source clinical trials software.
OpenMRS - OpenMRS is a community-developed, open source, enterprise electronic medical record system platform.
Castor EDC - Castor offers you a user-friendly and fully featured application for electronic data collection.
drchrono - An EHR built for your specialty:
Medidata CTMS - Medidata CTMS seamlessly integrates with Medidata Rave to provide real-time views into study progress without manual tracking.