I have downloaded FF and am trying it out. I appear to NOT be able to get past its launch, as follows.
When FF starts, it brings up a dialog box saying "FastFox requires that Assistive Devices is turned on." (and then a short paragraph describing how this is located in System Preferences). It even launches System Preferences. Sadly, what is described is for the OS **BEFORE** Mavericks. In Mavericks, there is something named "Accessibility" (rather than "Universal Access") and, so far, I have NOT been able to locate any checkbox for "Enable access for assistive devices" to check (as I could in the earlier OS). So I simply close out System Preferences and try to continue with FF.
The FF dialog box only gives me the options to select "I have turned on Assistive Devices" (its default) or "Cancel". When I click the former, FF merely cycles through and re-presents the dialog box (and opens System Preferences). When I click "Cancel" I then get a new dialog box for "Confirm Stop", with the options "Stop", "Cancel", and "Background" (to continue expanding text in the background). I take that latter option but cannot get even the basic tutorial action to work (i.e., typing "FMT " in a WP document).
Any ideas/suggestions?