Susy is a Sass add-on for grids recommended by Compass. You can read more about Susy in Chapter 10, Building grid-based layouts with Susy and Sass chapter of this book.
To demonstrate the Susy grid in the RoR app, the SCSS and HTML code of the Defining containers and columns recipe of Chapter 10, Building grid-based layouts with Susy and Sass, will be used again.
After performing the followings step you will know how to use the Susy add-on for Compass to create a grid-based layout for your RoR app: