In one form or another, Director has been around for nearly 20 years. It started in 1985 as a program written on the original 128 K Macintosh and published by MacroMind, a company started by Marc Canter in 1984. Marc's goal of creating software that combined graphics and sound wasn't entirely realized until 1989, when VideoWorks Interactive was renamed Director 1.0. By this time Director could handle color images and multichannel sound. At the same time, its lead programmer, John Henry Thompson, gave Director a scripting language he dubbed Lingo. Lingo could control many aspects of Director's engine, giving it something nobody else in the industry had. The closest competitor at the time was HyperCard, which was still working with black-and-white images only. Director has competition today, of course, but it's still leading the industry in software of its type.
Probably one of the reasons for Director's success is the speed at which people seem to pick it up. And a good part of that is the Director metaphor. You are the director, and you're making a movie, you can place any number of cast members on a stage, and control their actions through a score. You can remove them from the stage and use them again at a different point in your movie. And if you want to dive in and really control them, you can assign them a script! You see, it just makes sense, and it makes Director easier for newcomers to "get."