Microsoft Accessibility
http://msdn.microsoft.com/library/default.asp?url=/nhp/Default.asp?contentid=28000544

Microsoft

Abstract:

Microsoft Active Accessibility 2.0 is a COM-based technology that improves the way accessibility aids work with applications running on Microsoft Windows operating systems. It provides dynamic-link libraries that are incorporated into the operating system as well as a COM interface and application programming elements that provide reliable methods for exposing information about user interface elements. By following accessibility design practices and using Microsoft Active Accessibility, you can make technology products for your customers with accessibility needs.