This Wiki page is edited by participants of the HTML Accessibility Task Force. It does not necessarily represent consensus and it may have incorrect information or information that is not supported by other Task Force participants, WAI, or W3C. It may also have some very useful information.
Spec Review/User Agents
From HTML accessibility task force Wiki
From an accessibility perspective I think what is present here doesn't have issues. The vast majority of this section deals with DOM and web page access to browser elements. Terms like active window and such are used but they are very general and UAAG would really define how interactions within the browser itself were to be made accessible.