Here are some useful links for those interested in web accessibility as well as open source accessibility.

Guidelines & Standards

• Information and resources on Section 508 - legal policy for US government purchases requiring software accessibility.
• WAI - Web Accessibility Initiative
• Web Content Accessibility Guidelines (WCAG) 1.0 The first set of official guidelines from the W3C Web Accessibility Initiative (WAI). The European Union is looking to base their upcoming accessibility regulations on these guidelines.
• WAI interest group - Discussion list for standards in web accessibility.
• Web Accessibility Checklist from IBM.
• IBM's Java accessibility checklist - guidelines to making Java accessibility.
• Accessibility Information Resource Center For Developers at Adobe - Flash MX accessibility, PDF document accessibility and ActionScript accessibility.

Online Accessibility validators

There are now a few available and excellent online accessibility validators which check single webpages according to checkpoints of WCAG guidelines and then reports errors or warnings.

• WebXACT™ from Watchfire® Corporation

  WebXACT™ is a free and complete online accessibility validation service that can test single pages for quality, accessibility and privacy issues. The accessibility report will contain errors and warnings for "Automatic Checkpoints" and "Manual Checkpoints"; detailed and useful information (line numbers, instances/occurences, textual references to guidelines) will be included for web authors.

• Cynthia says™ from HiSoftware® Company

  "Cynthia says™" is a free online webpage accessibility validation service that identifies accessibility errors in webpage related to Section 508 standards and/or the WCAG guidelines. Just like WebXACT, it can also perform a "Complete Webpage Quality Check" for accessibility, privacy, searchability, metadata and even alt text attribute quality.

• Accessibility Valet from WebThing

  Description and summary to be written.

• WAVE 3.0 (Web Accessibility Versatile Evaluator) from WebAIM and sponsored by Temple University Institute on Disabilities

  WAVE 3.0 is another powerful, mature, free online webpage accessibility validation service that identifies accessibility errors and reports accessibility warnings about webpage related to Section 508 standards and/or the WCAG guidelines.

• HTML advanced validator (Firefox extension) by Marc Gueury

  This advanced HTML Validator (based on W3C Tidy and on OpenSP for SGML validation - just like W3C HTML validator) is a free, powerful, versatile, extended HTML validator. It can work offline. It can also report accessibility errors and warnings according to selectable accessibility guidelines (Section 508, WCAG Priorities 1, 2 or 3). Its accessibility report is viewable in the View Source window.

  This HTML advanced validator may also be downloaded from Firefox Add-ons: HTML Validator.

Open Source Assistive Technology Projects

• NonVisual Desktop Access open source screen reader for Windows, written in Python.
• LSR open source screen reader for Linux, written in Python
• Orca open source screen reader for Linux, written in Python

Accessibility for Desktop Environments

• Gnome Accessibility - Gnome Accessibility Project
• KDE Accessibility Project - an equally important toolkit on Linux
• Apple Accessibility - Moving forward with OS X.

Other resources

• Trace Center - Trace Center of the University of Wisconsin (research on technology for persons with disabilities).
• Home of LARS (Linux Accessibility Resource Site) at University of Toronto.
• Dive Into Accessibility - Another great, easy-to-understand resource on accessible website authoring.
• Color contrast analyzer by Juicy Studio: an excellent tool for checking if webpages use/have sufficient color contrast, sufficient brightness difference by comparing background and foreground (text) colors. This tool will measure accurately the degree of legibility of a webpage.