Free software form CDC. And more...

The Center for Disease Control and Prevention (CDC) offers a well known free statistical program, called Epiinfo. You can access it here:

http://wwwn.cdc.gov/epiinfo/

More resources:

Openepi is a free software program developed by the Rollins School of Public Health from Emory University in Atlanta, GA.

http://www.openepi.com/OE2.3/Menu/OpenEpiMenu.htm

Epidata. Free software by JM Lauritsen et al., from Denmark.

http://www.epidata.dk/

Netepi
http://sourceforge.net/projects/netepi/





Software for Systematic reviews and meta-analysis:

Revman is the software from the Cochrane Collaboration to feed in data and produce a systematic review:
http://ims.cochrane.org/revman


Epimeta, from the CDC
http://ftp.cdc.gov/pub/Software/epimeta/


MIX
http://www.mix-for-meta-analysis.info/

Software for Clinical Trials:

https://community.openclinica.com/