Justice League: The New Frontier is a 2008 direct-to-video animated film adaptation of the DC Comics limited series DC: The New Frontier. The film was written by Justice League writer Stan Berkowitz, with Darwyn Cooke, the writer and artist of The New Frontier, serving as story and visual consultant.
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Justice League: Crisis on Two Earths is a 2010 original direct-to-video animated film released on February 23, 2010. It is based on the abandoned direct-to-video feature, Justice League: Worlds Collide, which was intended as a bridge between the then-concluding Justice League animated television series and its then forthcoming sequel series Justice League Unlimited. The movie project was shelved because of insufficient staff to produce the movie and the TV show simultaneously. Crisis on Two Earths was reworked from the Worlds Collide script to remove references to the TV series' continuity.
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