Lynx View web page is a text only browser that is often used by persons who are blind in conjunction with screen reading software. The Lynx View web page will display a web page in text only fromat as it would appear with the Lynx browser.
The Web Accessibility Initiative (WAI) is the World Wild Web Consortium's (W3C) official accessibility arm and has resources including web content accessibility guidelines and a detailed checklist for accessibility.
Job Access With Speech (JAWS) is a popular screen-reader used by the visually impaired.
Section 508 details the Federal government's accessibility guidelines.
The US Department of Justice's accessibility checklist is not required however it is a valuable resource.
The Macintosh OS has many Accessibility Features built into the operating system.