The Accessibility Stuff

"The power of the Web is in its universality. Access by everyone regardless of disability is an essential aspect." Tim Berners-Lee, W3C Director and inventor of the World Wide Web

What is accessibility?
Accessibility ensures that content is accessible : can be navigated and read by everyone, regardless of location, experience, or the type of computer technology used.
What users require accessibility?
Blind Users using a screen reader, Partial or Poor Sight Users that need to enlarge the text on a site, Users with forms of Color Blindness, Deaf Users, Keyboard only users (no mouse), Voice Only users, Epileptic Users (need to avoid seeing flickering between 2 and 55hz), Web Users with a first language other than English and Users from outside your industry (explain industry specific terminology and acronyms and strive for clear, concise English text), Users on PDA's and mobile devices (width can be as small as 120px and horizontal scrolling is not an option : uneven support for large images, Javascript, Flash, CSS), WebTV (maximum width of 575px and horizontal scrolling isn’t possible), Users on slow connections, etc.
What is section 508?
Section 508 of the Rehabilitation Act requires access to electronic and information technology procured by Federal agencies. Accessibility standards for the various technologies covered by the law are also incorporated into the Federal government's procurement regulations.
Where can I find the actual law, Federal Acquisition Regulation, and the final Standards?
Access Board Government Documents
Recommended Policies and Guidelines for Federal Public Websites June 9, 2004

ONLINE ACCESSIBILITY TOOLS
WatchFire WebXACTis a free online service that lets you test single pages of web content for quality, accessibility, and privacy issues. note : Restricted to one check per minute.
Online Hyperlink Checker
W3C Markup Validation Service; checks HTML and XHTML for conformance to W3C Recommendations and other standards
W3C CSS Validation Service
Robots.txt Checker
AnyBrowser HTML Validation
AnyBrowser Website Viewer

ACCESSIBILITY ARTICLES
What Is Web Accessibility? by Trenton Moss
Dive into Building Accessibility by Mark Pilgrim
Building Accessible Websites by Joe Clark
High Accessibility, High Design
Benefits of Web Standards
The Business Case for Web Accessibility

ACCESSIBILITY RESOURCES
Web Accessibility Initiative (WAI)
Checklist for 508 compliance, provided by the nonprofit WebAIM (Web Accessibility In Mind).
Accessibility Toolbar (NILS) -The Web Accessibility Toolbar simulates the experience of different users.
Delorie Lynx Viewer - View your pages as a text-only browser would, you can readily see the order the words would be read by a screen reader.
Opera - Checks alt-text, how tables linearize, and ensures that pages work with style sheets turned off.
UsableNet : Macromedia Dreamweaver extensions.
USPS AS-508 Section 508 Handbook in HTML or PDF
USPS AS-508-A Section 508 Technical Reference Guide in HTML or PDF
Vischeck : Simulates colorblind vision.
Web Publishing Accessibility Wizard for Microsoft ® Office : Converts PowerPoint presentations, Word documents, and (in the future) Excel spreadsheets to accessible HTML.
New York Public Library Style Guide

ACCESSIBILITY BOOKS
Building Accessible Websites Joe Clark
Designing With Web Standards Jeffery Zeldman

ACCESSIBILITY COMPANIES
PCTest : tests your site for accessibility, localization, interoperability and more.