The W3C defines Accessible Rich Internet Applications (ARIA) as a syntax for making dynamic web content and custom UI accessible. Microsoft Edge recognizes the ARIA role, state, and property information and exposes it to assistive technologies, which in turn can use the Microsoft UI Automation APIs to retrieve the information.
The Microsoft Edge rendering engine (EdgeHTML) builds an accessible projection of web pages, conforming to the following W3C specifications:
The HTML Accessibility API Mappings specification defines how HTML elements and attributes map to ARIA and UI Automation objects.
The Core Accessibility API Mappings specification defines general principles for building the accessibility tree and mapping ARIA elements and attributes to UI Automation objects.
The Accessible Name and Description: Computation and API Mappings specification defines how to compute the name and description of accessible objects given the HTML and the ARIA elements and attributes values available for the accessible elements.
For more information about the accessibility architecture in Microsoft Edge, check out the Building a more accessible web platform blog post.