Note: These are rough notes from the WWW2007 conference.
Assistive technologies are tools that PWD use. They transform content, accept input from alternative devices, and require particular semantics.
There aren’t enough semantics in todays languages. Things other then links and forms need tab order. Some of these issues have been caused by AJAX and flash.
One practice is to make sure keyboard support is available. You need to be able to navigate through elements by giving them focus. Users with disabilities don’t often seen a whole page. They need to be able to get to another part of a page.
AT needs to be able to gain access to complex widgets, like tree controls, grids, and menus.
AT needs to know about the classic organization of the page, like sections, headers, and groupings.
There needs to be a way to know that content has been updated. The users should be updated in an effective but non-obtrusive way.
There needs to be a way to identify widgets.
Oatmeal Stout - Justin Thorp's blog 