The conference was supposed to be held at the Beverly Hilton Hotel in Beverly Hills, Calif., from Oct. 8 to Oct. 11. It will now take place Feb. 10 to Feb. 14 at the same location.
Many tech events have been postponed or canceled in the aftermath of this month's terrorist attacks on the World Trade Center and the Pentagon.
"Many QuickTime developers and customers asked us to reschedule QuickTime Live to a less stressful time," said Philip Schiller, Apple's vice president of worldwide product marketing. "We'll look forward to seeing them all in February."
QuickTime is Apple's technology for handling video, sound, animation, text and virtual reality.
Developers do have a lot on their plates right now. Microsoft's Windows XP operating system is scheduled to debut Oct. 25 in New York. And Apple's own update to its Mac OS X operating system will launch this weekend.
Apple had already canceled its Expo 2001, scheduled to take place in Paris from Sept. 26 through Sept. 30, after the attacks.