Last I checked (a year or so ago, but bug report not updated to indicate current release differs much) CheerpJ provides the full Java Accessibility API, however, from the bug report on this issue, the API calls are "not interpreted and converted by CheerpJ to corresponding browser functionalities". So from a practical standpoint currently lacks support, but have stated they may improve this in future. I haven't had the time to attempt it, but based on the API they expose [when I looked, may have changed since] to talk to the runtime from the browser, it looked feasible but not fun to wire up at least basic screen reader / automation support. From my experience with a Java application converted to running on its jvm, the performance is on par to running it previously hosted on Oracle jvm via Internet Explorer. It is good, except I hate I can't copy using ctrl-ins or shift-del because it requires ctrl-c pressed after initiating copy (presumably most people just press ctrl-c twice so minor inconvenience or maybe its a quirk of our installation).