Microsoft Active Accessibility

Microsoft Active Accessibility (MSAA) is an accessibility API introduced by Microsoft in 1997 that enables assistive technologies such as screen readers to interact with user interface elements in Windows applications. MSAA provides a standardized way for applications to expose information about their UI elements — including names, roles, states, and values — so that assistive technologies can read and manipulate them. In the context of web accessibility, screen readers that rely solely on MSAA have more limited capabilities than those that also use the Document Object Model (DOM), because MSAA does not provide the complete tree structure of a web page. MSAA was largely superseded by UI Automation (UIA), a more capable accessibility framework introduced in Windows Vista, though many applications still support both APIs for backward compatibility.