What is Macromedia Flash MX?

Have you ever seen a site that has a lot of animation? or that takes a while loading but the results are really cool?  (video, animation, music, etc.) well that's a flash movie, and they are used to do more complex sites than the ones made on plain HTML, Macromedia Flash MX  is the software that allows you to to that. It is the great creating tool of animation. This Is what I will be using to make my project.