Founded in 2002, the Tribeca Film Festival was initially intended to help revive Lower Manhattan in the wake of the 9/11 terror attack. While it has proved popular with local audiences, it has struggled to gain legitimacy with cinephiles and critics, and despite gaining a reputation for its strong documentary offerings it has been unable to crack the upper echelon of film festivals, like those in Cannes, Venice, Berlin and Toronto.  Last year the festival took to heart some of the complaints about sprawl — in terms of both offerings and location — and shaved by 25 percent the number of feature films it showed, while concentrating the screenings in a narrower area of Manhattan. The eighth Tribeca festival is scheduled to begin on April 22.  Tribeca Enterprises was started in 2003 by Jane Rosenthal; her husband, Craig Hatkoff; and her longtime business partner Robert De Niro. It is an umbrella company overseeing not just the festival but also a growing number of enterprises, including the Tribeca Cinemas and the Tribeca Film Festival Doha, expected to begin in Qatar next November.  In a statement on Tuesday, Robert Redford, president of the Sundance Institute, which counts the Sundance festival among its programs, said of Mr. Gilmore: “I support completely his decision. The timing is right to move on.”  Mr. Gilmore joined the Sundance festival as its director in 1990, after running the programming department of the film and television archive at the University of California, Los Angeles. Over the years he helped push Sundance to prominence in the United States by bringing a number of off-center films to the fore, among then “Reservoir Dogs,” “Hoop Dreams” and “Little Miss Sunshine.” In recent years he helped shift the festival’s focus to include a growing number of films from abroad, including, as the opening-night film of the most recent festival, “Mary and Max,” a stop-action animation from the Australian writer and director Adam Elliot.  Along the way Mr. Gilmore’s sandy beard and often raspy voice became familiar to Sundance habitués, who frequently found him on hand to introduce films and filmmakers.  Mr. Gilmore did much of his work from an office in Los Angeles, but he also spent much time at the Sundance quarters in Utah and has personal ties that frequently took him abroad.  Brooks Addicott, a spokeswoman for Sundance, said the organization, having just wrapped its 25th festival in January, might take some time to decide on its next step. She pointed out that the festival’s programming staff, headed by John Cooper, a 20-year Sundance veteran, remained in place.  “We’re in a contemplative place,” Ms. Addicott said. “We don’t have a sense of urgency.”  A version of this article appears in print on , on Page C3 of the New York edition with the headline: Shakeup in Film Festivals As a Familiar Face Moves. Order Reprints| Today's Paper|Subscribe
Geoffrey Gilmore has resigned his post as director of the Sundance Film Festival to become the creative director of Tribeca Enterprises.