With a few small tweaks, this can be made extremely accessible. I think that jQueryTools is, in general, a much cleaner and simpler package than jQuery-ui. Because jQuery-ui wraps the elements you give it in its own complex HTML, uses lots of inline styles, and requires an extensive CSS framework, it can be very difficult to add necessary accessibility tweaks on the fly. They have attempted to build them into the html, but this requires testing each time a new version of a tool is created. jQueryTools does not modify the html you specify and thus adding accessibility tweaks on the fly is simple and straightforward. This example requires about 5 extra lines of Javascript and a few additions to the HTML. compare this with a similar jQuery-ui accordion demo.