It is an open source programming language mainly used for developing technical tools to be used for the productive results in various areas such as business and other computer related jobs. XUL stands for XML as it is based on XML programming language. It can also be called a user interface language.

Cascading Style Sheets popularly known as CSS is quite important when it comes to web designing. It is basically a style sheet which allows one to easily link to other documents in your website. A single CSS sheet can control the font, positioning, colour and style information of an entire website. Here are some great CSS tools which are used by web designers across the world to boost up their designing skills and reduce designing time.