Redford opens "festival of dissent"
The festival's founder said he liked to think of Sundance as a "festival of dissent" in which diverse directors and producers could put forward their views.
"This is really a festival about different voices in film that really reflect, a little more accurately, the world we live in," he said.
This year's festival opened with the comedy Happy Endings, starring Lisa Kudrow and directed by the man behind The Opposite Of Sex, Don Roos.
It focuses on the lives of three people, played by Kudrow, Tom Arnold and Maggie Gyllenhaal, which all overlap.
Festival director Geoff Gilmore said it had been chosen because of the way it explores modern American values.
The festival has shown controversial films such as Reservoir Dogs, The Blair Witch Project and Super-Size Me since it was first started in 1981.
This year's other offerings include The Chumscrubber, an ironic take on life in the suburbs of America, and Murderball, a documentary about quadriplegic athletes.
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