A system is accessible if it can be used by any user regardless of computer used, the speed of connection, the browser used, the UI and the alternative devices are used. Accessibility is therefore not only difficult but also permanent all those situations that, regardless of physical or mental deficiency, are due to the possible use of the contents of the Web.

USA requires first by law the requirements for accessibility with the Section 508 (1998). In Italy, the accessibility is governed by the so-called Legge Stanca (2004). The Italian legislation provides 22 technical requirements based on the guidelines of the W3C WCAG 1.0 to be met by all web applications, although not directly available online.

A specific section of the W3C, the WAI ARIA, was developed to solve all the accessibility problems that affect the management of applications and dynamic web content. The issues on which he works are essentially two:

• Notify the assistive technology of dynamic changes occurring in the interface;
• Managing the way in which these changes are provided to assistive technology.

WAI-ARIA provides a framework for adding attributes that identify the characteristics of the interaction, how they relate to their current status. It describes new navigation techniques to mark the regions and structures including common Web technologies to map controls and live regions Ajax.

In the design of the web application we tried to respect all the parameters by inserting the states and properties provided by WAI-ARIA, with the goal of providing full accessibility.