"Cynthia is a web content accessibility validation solution, it is designed to identify errors in design related to Section 508 standards and the WCAG guidelines. The main purpose of this portal is to educate web site developers in the development Web Based content that is accessible to all. This online test only validates one page at a time. Note this demo will test about one (1) page per minute / per site." Check out the validator...

This online accessibility validator from Web Thing, is a subset of the larger Site Valet QA suite and provides useful output that really is best seen in a modern CSS and DOM compliant browser. I don't know about it's overall accuracy, but as a hand-coder of HTML, this is by far the best validator output I've seen. Visit the Valet...

This is an extensive listing of information collected by the W3C's Web Accessibility Initiative (WAI) about evaluation, repair, and transform tools to be used by Web content developers and users to make the Web more accessible. See the listing...

"WAI, in coordination with organizations around the world, pursues accessibility of the Web through five primary areas of work: technology, guidelines, tools, education and outreach, and research and development." This is an excellent resource center for all things related to accessibility on the web, and is a product of W3C, the World Wide Web Consortium. Visit the website...

This is the Dept. of Justice's take on section 508, and includes references to the statute itself (in both HTML and PDF) formats. Visit the website...

This accessibility validator is a product of Pennsylvania's Initiative on Assistive Technology (PIAT), and focuses on programmatic validation of section 508 access issues. Ride the WAVE...

"Bobby tests web pages using the guidelines established by the World Wide Web Consortium's Web Access Initiative as well as Section 508 guidelines from the Architectural and Transportation Barriers Compliance Board (Access Board) of the U.S. Federal Government." This is perhaps the most commonly used automated accessibility validator. Go to Bobby...

"Betsie stands for BBC Education Text to Speech Internet Enhancer, and is a simple Perl script which is intended to alleviate some of the problems experienced by people using text to speech systems for web browsing." Check it out...

Software for simulating the three main types of color blindness and correcting images for colorblind viewers. The software can either be run over the internet or on your local machine, and it's free. Visit the website...

From Aries Arditi, Ph.D, via Lighthouse International, "This brochure contains basic guidelines for making effective color choices that work for nearly everyone. To understand them best, you need to understand the three perceptual attributes of color: hue, lightness and saturation, in the particular way that vision scientists use them. Full explanations of these terms are provided in the pages that follow." Visit the website...