Recently posted to the mailing list, there will be an International XUL Meetup day this week, Tuesday, April 6th. There's one in my area scheduled for Chili's in Westford at 7pm. The group appears to organize these meetups on the first Tuesday each month, although I know nothing about them so far, so I don't know when they formed or how long they've been meeting. The only XML user interface langauges that come to mind at this point include XSLT, XSL-FO, XAML, and of course MXML, but it appears that XUL has its own specification all by itself.

I'd be interested in attending some time, just to see the scope of the discussion in case it extends to the general class of XML UI languages. For more information see: