The Purified (2003)

The filmmakers who created the Dogme Manifesto reflect, argue, and watch clips of their own films.
Filmed during the course of a day long meeting between Dogme adherents Lars Von Trier, Soren Kragh-Jacobsen, Thomas Vinterberg, and Kristian Levring, the film isn't afraid of confronting the contradictions and flaws of the Dogme manifesto. Levring has the most insightful comments, and it's clear that Vinterberg was most comfortable with stretching the rules. Vinterberg's Festen scenarist Mogens Rukov is also around with some interesting thoughts.