OHNews 2013 Readers Choice: 'Open Source' Health IT Systems

As we head towards the end of the year, the global 'open source' software movement continues to grow and strengthen, especially in the field of healthcare. Based on the number of hits by readers of Open Health News (OHNews) on links to our brief profiles of 'open source' Health IT systems, the following are their top choices of interest over the past year:

VistA System  – major variants include:
  o VA VistA & OSEHRA
  o vxVistA
  o OpenVistA
  o WorldVistA
  o OHUM VistA
  o Hakeem VistA
Resource & Patient Management System (RPMS)
District Health Information System (DHIS2)
'Blue Button'
3D Slicer
Clear Canvas
Hospital OS
KitWare Systems

* See links to other 'open source'  and 'public domain' health IT systems in the OHN Resources Section, e.g. Epi Info, GIMIAS, iHRIS, NEDSS, OpenEMPI, PHIN, Ushahidi, ...

Which is your favorite 'open source' Health IT software solution? Do you have another notable 'open source' Health IT system you would like to recommend to our readers?