PARK CITY, Utah (Reuters): Each year documentaries at the Sundance Film Festival are among the best movies here, and in 2012 nonfiction works on subjects from the healthcare crisis to the war on drugs and rape in the military are wowing crowds and spurring calls to action.

Sundance is the premiere US film festival for movies made outside of Hollywood's mainstream studios, and it is among the world's elite gatherings for documentary makers. Sundance backer and activist Robert Redford, is an avid supporter of the form.