Correction: The current official accessibility API for Windows is UI Automation. IAccessible2 (IA2) is an unofficial extension of the very old Microsoft Active

Correction: The current official accessibility API for Windows is UI Automation. IAccessible2 (IA2) is an unofficial extension of the very old Microsoft Active Accessibility (MSAA) API. While IA2 has been crucial in making non-Microsoft browsers and other applications accessible, I wouldn't recommend that any new code implement it. Disclosure: I'm a developer on the Windows accessibility team at Microsoft, working on UI Automation and Narrator among other things.