John Oliver, Jon Stewart, Jimmy Fallon, Seth Meyers and more had cameos during the July 21 episode of "The Late Show With Stephen Colbert."

The September event, coming to New York for the first time, will also include panel discussions with Robert Downey Jr., David Letterman and Richard Ayoade.

NEW YORK — Stephen Colbert has received support from his fellow late-night TV hosts following his cancellation by CBS, including from his predecessor. David Letterman, who was the host of “The Late Show” for 22 years, used his YouTube channel to post a video montage of the many times he ripped into CBS over the years for various reasons.

In 1993, he started working as a writer-producer on Late Night with David Letterman, which aired on NBC. Burnett ultimately made the move to CBS with Letterman when The Late Show was picked up at that network.

Joaquin Phoenix deeply regrets his infamous David Letterman interview. The “Joker” actor, 50, appeared” Tuesday and looked back on the infamous exchange he had with Letterman, 78, in the same NYC studio over 15 years ago.

There was truly nobody like David Letterman. The longest reigning late-night host in history, Letterman was quick-witted, irreverent, and hilarious. But it wasn't all laughs—for David Letterman, fame came at a terrible price. So what was Dave's life like ...