At the end of this chapter, we're going to give you a brief reference to the Fusion Theming System. It was introduced only a few months ago and it's still under heavy development. It's a base theme, meaning that you can create your own subthemes easily, using the Fusion Starter, a commented starter theme created especially for this reason. It uses a 960px or fluid 16-column grid, and its main advantage is that, with the help of Skinr module, it creates layout and style configuration options that the site administrator can control using the website's User Interface, without messing with CSS. So, let's see how to install it, and how to use it for simple customizations.