AT products work with MSAA enabled applications in order to provide better access for individuals who have physical or cognitive difficulties, impairments, or disabilities.
As part of Microsoft's ActiveX branding push in March 1996, OLE Accessibility was renamed ActiveX Accessibility (sometimes referred to as AXA) and presented as such at the Microsoft Professional Developers Conference in San Francisco, March 1996.
MSAA was originally made available in April 1997 as part of the Microsoft Active Accessibility Software Developers Kit (SDK) version 1.0.
Programmatic exposure for assistive technology applications on Windows has historically been provided through MSAA.
However, newer applications are now using Microsoft UI Automation (UIA), which was introduced in Windows Vista and the .NET Framework 3.0.
The following Active Accessibility versions have been released:[2] The motivating factor behind the development of MSAA was to allow an available and seamless communication mechanism between the underlying operating system or applications and assistive technology products.
Applications (e.g., word processor) are called Servers in MSAA because they provide, or serve, information about their user interfaces (UI).
Accessibility tools (e.g., screen readers) are called Clients in MSAA because they consume and interact with UI information from an application.
The system component of the MSAA framework, Oleacc.dll, aids in the communication between accessibility tools (clients) and applications (servers).
The four critical pieces of information on which the AT relies to help users interact with applications are an element's role, name, value, and state: Microsoft provides a complete list of controls and their functions.
For example, the property values returned from scroll bar and trackbar accessible objects can indicate percentages in strings.
For example, there is no text object model to help assistive technologies deal split buttons which combine multiple UI elements into one.
However, MS-TOM's complexity and limited initial adoption outside of Microsoft hampered access to rich text.
So information can be shared between the two APIs, an MSAA-to-UI Automation Proxy and UI Automation-to-MSAA Bridge were developed.
Accessible Rich Internet Applications (WAI-ARIA): There is a general mapping from ARIA attributes to MSAA properties.
More implementations of MSAA in applications and AT products can be found by searching on the Microsoft Accessibility sites or on the AT Information website.