Aqua Dock Is a free program that allows you to have an “OS X” style, nice animated launchbar / taskbar on your screen that reacts to your mouse when you mouse over it. Users can customize the look of each item on the dock and set various animation options for when the mouse is over an item on the dock. It is very easy to configure.

In short, Aqua Dock is a task bar and a Windows program launcher that does it with Apple’s style.