Anyone know of any good documentation on what Opera supports as far as ECMAScript, JavaScript, DOM, and DHTML?

I have a document that was built for viewing with IE 5. I have been able to scale it back for IE 4 and am working on compliance with Navigator 4 (using the DynEl API in the Rhino book).

Regretably the 3rd Ed of the Rhino came out in '98. It doesn't even mention Opera, and as far as I know, there isn't a newer edition.