The release of Internet Explorer 9 has brought about new accessibility challenges which have, as a result, necessitated many assistive technology manufacturers to release new versions of their products. IE 9 runs on 32 and 64-bit versions of Windows Vista, Windows 7 and Server 2008, thus these issues will not affect users of earlier versions of Windows where using IE 9 is not an option.
The biggest accessibility-impacting challenge resulted from a change to the method used by the browser to render content on the screen. The new method, Direct2D, paints content directly to the screen instead of allowing rendering to be handled by the operating system. This means that legacy versions of screen readers cannot build an off-screen model for exploration of the screen by screen review cursors that simulate the mouse pointer. It also prevents the font smoothing feature of screen magnification products from functioning within the browser. The new rendering technique has necessitated Microsoft to expose content using UI Automation, the accessibility API used in Windows 7. This has required assistive technology manufacturers to develop new versions of their product which obtain the browser information from UIA instead of using MSAA or screen scraping techniques as well as the document object model (DOM).
In the Accessibility Considerations section of their Release Notes for Internet Explorer 9, Microsoft documented the accessibility issues that were known at the time IE9 was released. JAWS for Windows, Window-Eyes and NVDA have all released versions of their product which claim to work with IE 9. These releases obtain their content from UIA and, in so doing, overcome many of the accessibility issues documented in the release notes. JAWS users should upgrade to version 12.0.1158, which can be obtained directly from the Freedom Scientific website or by performing a Check for Updates within JAWS 12; Window-Eyes users should upgrade to Window-Eyes 7.5; Users of Dragon Naturally Speaking should upgrade to version 11; The current version of NVDA that supports IE 9 is version 2011.1.1. Users of screen magnification software should consult the manufacturer to determine which font smoothing settings to adjust or to upgrade to the latest version.