Before we start creating our new theme and UIs, we need to install some tools onto our computer. These tools will help us write our theme in Ext JS, because we are going to use Compass and SASS to generate our CSS code and give a new feel to our application.

SASS, also known as Syntactically Awesome Style Sheets (http://sass-lang.com/), is an extension of CSS that allows us to use variables, nested rules and mixins, and it's more thoroughly compatible with CSS syntax. This will allow us to create style sheets with less effort.

COMPASS (http://compass-style.org/) is a SASS framework designed to make more work more smooth and efficient. Let's call it a library of tools and the best practices for manipulating SASS. In the end, the compiled output will be CSS files.

In order to use both tools (SASS and Compass), we need to have Ruby installed on our computer. Ruby is a dynamic language and is popular among web developers worldwide. For the moment, don't worry if you...