There has been much discussion, and some arguments, about how to determine the accessibility of websites. Unfortunately, this is often polarised around two simplistic choices: A compliance/conformance based approach that usually involves a checklist of criteria; or, some form of user testing by people who have different disabilities and/or who rely on different assistive technologies. Both approaches have their strength and limitations, and neither can provide a reliable declaration about the accessibility of a site on its own.
Worldspace FireEyes « Deque Systems | Software, Training, and Consulting for Web Accessibility and Section 508 Compliance
Worldspace FireEyes is an unprecedented, nextgen web accessibility tool that ensures both static and dynamic content within a web portfolio are compliant with standards such as Section 508, WCAG 1.0, and WCAG 2.0.
A guide to understanding and implementing Web Content Accessibility Guidelines 2.0
W3C Working Group Note 14 October 2010