The goal of accessibility is to ensure that information or services delivered through websites are available to and usable by the widest possible audience. According to the American Association of People with Disabilities (AAPD), there are currently over 54 million Americans living with disabilities. As society becomes more dependent on the Internet for information and services, it is critical that the web be usable by everyone. It is not only the right thing to do, it's the law. In 1998 Congress amended the Rehabilitation Act to include Section 508. Section 508 requires government agencies and institutions receiving federal dollars to ensure that all electronic and information technology applications are accessible to individuals with disabilities.
The Americans with Disabilities Act (ADA), which became law in 1990, is a civil rights law that prohibits discrimination against people with disabilities. The ADA generally requires employers, state and local governments, and places of public accommodation to offer reasonable services or tools to insure that people are not discriminated against on the basis of disability. The ADA defines a person with a disability as someone who has a physical or mental impairment which substantially limits one or more major life activities (such as hearing, seeing, speaking, thinking, walking, breathing, learning, or performing manual tasks).
According to the U.S. Department of Commerce, Bureau of the Census, "About 1 in 10 Americans have some kind of disability, and 1 in 10 have a severe disability. And, wiht the population aging and the likelihood of having a disability increasing with age, the growth in the number of people with disabilities can be expected to accelerate in the coming decades."
Section 508 covers two key issues. The first is that when federal agencies "develop, procure, maintain, or use electronic and information technology" this technology must be accessible to federal employees with disabilities. The second is that members of the public who have disabilities must be able to gain access to the information or services offered by each agency.
Accessibility Testing
A good tool to use for testing your site for Section 508 accessibility compliance is The Universal Access Validator (http://condor.gmu.edu/josh/validator/). This tool will enable you to enter the url of the webpage and will generate a report detailing the guidelines which the webpage passes and fails. It also allows you to view the page as a text-only version, as a no-stylesheets version (to make sure the information is understandable without CSS), and as a no-Javascript version (to see how the page displays for users with browsers that don't support Javascript). All are useful in determining whether your webpages are accessible and usable.
"The power of the Web is in its universality. Access by everyone regardless of disability is an essential aspect." - Tim Berners-Lee, World Wide Web Consortium (W3C) Director and inventor of the World Wide Web