K-PACS: http://www.k-pacs.net
Osirix: http://www.osirix-viewer.com/Downloads.html
Weasis: http://www.dcm4che.org/confluence/display/WEA/Home
Clear Canvas: http://www.clearcanvas.ca/dnn/
eFilm: http://estore.merge.com/na/estore/content.aspx?productID=405
Adobe Acrobat Reader: http://get.adobe.com/reader/