What is the Accessibility API's role?

• AT today uses many techniques to obtain the information needed to provide access:

• • Make standard system calls for things that help them
  • Patch/replace/chain video drivers to build Off-Screen Models of the contents of the screen; keyboard drivers in order to redirect keyboard control
  • Use application-specific APIs to get information from specific applications

• Accessibility APIs replace some/most/all of these with supported programming interfaces

• • Some Accessibility APIs may be comprehensive enough to replace the need for an Off-Screen model