Castor EDC - Castor offers you a user-friendly and fully featured application for electronic data collection.
OpenClinica - OpenClinica is an open source clinical trials software.
GNU Health - GNU Health is a Free/Libre project for health practitioners, health institutions and governments.
Snthesis - Automatically Integrate and Harmonize all your Research Data into one clean database. Source Agnostic. Search Everything.
Viedoc - EDC, ePRO, eCRF, eTMF, CDMS, electronic data capture, clinical trial and PMS software
OpenMRS - OpenMRS is a community-developed, open source, enterprise electronic medical record system platform.