In a statement on the Web World Web site, James Fawcette, president of show organizers, Fawcette Technical Publications, says: "We are very saddened and outraged by the attacks on New York and Washington, DC on September 11, 2001.
"Our hearts and prayers go out to all of the people affected by this crime against America.
"Due to unforeseen difficulties associated with air travel and in order to give all of those who planned on participating at Macromedia Web World time to adjust to the events that have transpired, FTP Inc. and Macromedia have decided to postpone the event.
"Efforts are in process to reschedule the event. We will post updates as they become available. Thank you for your understanding and support during this crisis."
The event was due to open on Monday September 17. It's the company's main event for its customers, and involves special panels and workshops covering all its products. Keynote speeches were promised from both Macromedia president Kevin Lynch and chief technology officer Jeremy Allaire.