Shockwave is a plug-in that displays Macromedia Director movies within a Web browser. Director has been around for quite some time and has always been a favourite with multimedia producers. Not only does it handle 2D animation in a very intuitive way, its scripting language, 'Lingo', gives extensive control for manipulating 'sprites', sound channels and for general interactivity and navigation.
Although 'Shocked' files are compressed very efficiently, they still tend to be on the 'heavy' side compared to other Web animation techniques. The main advantage of Director/Shockwave is in its ease of creating the animation in the first place and, of course, the scope for interactivity.