Mark Williamson said:
All of these notations are standardised and can be used for any signed language. Unfortujnately, nonve of them are widespread and the only universally understood option would be to use video clips, which is horrendus (vrml might work too, but it's still not a viable option)
I like that latter idea, though it's probably way beyond the scope of the MediaWiki project. Presumably it should be possible to have some kind of VR mannequin that takes any of these alphabets and produces understandable sign.