Paul Joseph Schrader is an American screenwriter and film director, renowned for his characters that fall into desperation while their world crumbles around them. Despite his credentials as a director, Schrader has received more recognition for his screenplays directed by others. Martin Scorsese filmed his script of “Taxi Driver.” The film was nominated for a 1976 Golden Globe Award and provided the acclaim and funding that enabled Schrader to direct “Blue Collar,” starring Richard Pryor and Harvey Keitel.
Besides “Taxi Driver,” Scorsese has also filmed Schrader’s scripts for “The Last Temptation of Christ” and “Bringing Out the Dead,” and directed “Raging Bull”, which Schrader co-wrote with Mardik Martin.
Source - Wikipedia http://en.wikipedia.org/wiki/Paul_Schrader