Yes it appears to be broken. I'm considering removing that feature because it doesn't necessarily fit the purpose of the site.

That's alright. I'll link to the demo on other sites in their descriptions.

Where would you suggest hosting demos if one does not have their own domain name?

edit: not sure why I wrote domain name, I meant to say website.

@Conscious Probably GitHub. I don't see too many Java applets being demoed there, but I imagine its possible.