HTML and CSS Reference
makes non-technical recommendations about how web applications should be made accessible. However, unlike in
the United States, this is just a standard and not the law.
Many of these laws and standards are based around the Web Content Accessibility Guidelines (WCAG) published by
the World Wide Web Consortium (W3C). This specification outlines the principles that web developers should fol-
low in order to create accessible websites.
You can view the full WCAG (version 2.0) specification on the W3C website at
Browsing the web can be a challenging experience for users with visual impairments. Depending on the level of the
impairment, these users may use a computer program called a screen reader to navigate between pages and consume
content. Screen readers read aloud the page content and enable users to browse using only their keyboard. This
means that developers have a responsibility to create websites that can easily be understood by screen readers.
Take a look at some of the most popular screen readers in the following list. I recommend you download or activate
a tool appropriate for your operating system so you can test your code as you add accessibility features to your web-
• Apple Voice Over —Apple's Mac OS X operating system comes with a built-in screen reader called
VoiceOver ( http://www.apple.com/accessibility/voiceover/ ). This program enables
users to navigate their laptop or desktop computer using a number of keyboard shortcuts. You can activate
VoiceOver using a keyboard shortcut: Cmd + F5.
• Orca for Linux —The most popular screen reader amongst Linux users is Orca ( ht-
tp://projects.gnome.org/orca/ ). Orca is a free and open-source piece of screen reading soft-
ware that was originally developed by Sun Microsystems to enable users with disabilities to access the vari-
ous programs on their computer (not just websites).
Linux distributions that use the GNOME desktop environment, such as Ubuntu, often come with Orca pre-
installed. The program can be accessed from the main menu or the new unity launcher in the latest versions
• NVDA for Windows —For Windows users, there is a free and open-source screen reader called NVDA, for
Non-Visual Desktop Access. You can download NVDA from the project's website at
Figure 9-1 shows VoiceOver in action. Notice how the program highlights the text that is currently being spoken by
placing a thick black box around it. The semi-transparent black box at the bottom of this screenshot shows the text
the screen reader spoke.