When making software procurement decisions, educational entities need to look critically at which products in a given software category will best serve the needs of all students, without excluding some on the basis of disability. Several resources for making these decisions are provided in the AccessIT Knowledge Base article How can I tell whether a software application is accessible? 
One software category used by nearly all educational entities is the web browser. In order to be accessible, a web browser, like any other software product, must have an interface that is accessible. For example, the browser must be operable by keyboard only (for people who are unable to use the mouse) and must be compatible with assistive technologies such as screen readers. In addition to having an accessible interface, web browsers must be capable of presenting web content in an accessible way, provided that the web author practiced accessible web design techniques.
The World Wide Web Consortium (W3C) has developed twelve accessibility guidelines specifically for user agents, a product category that includes web browsers. The User Agent Accessibility Guidelines (UAAG) are described further in the AccessIT Knowledge Base article Are there accessibility guidelines for web browsers? .
In addition to developing and maintaining these guidelines, WAI™ engaged in a review of a variety of user agents on a range of platforms. The purpose of the review was to verify the utility and application of the UAAG, and WAI cautions that the review should not be interpreted as a definitive statement of product conformance. Nevertheless, the review provides an interesting glimpse at how browsers and other user agents are applying the guidelines in addressing accessibility. Individual evaluations and other information can be found in the WAI document User Agent Implementation Report for Second Candidate Recommendation .
-  How can I tell whether a software application is accessible?
-  Are there accessibility guidelines for web browsers?
-  User Agent Implementation Report for Second Candidate Recommendation