There was a thread recently on the SVG list about SVG + XForms being the replacement for Display Postscript.
Well, almost. A lot of that discussion got bogged down on ECMAScript. Given a choice, I don't want to write a multilanguage app where one of the critical pieces is ECMAScript. However, that doesn't seem to be a requirement. (A couple of people noted that we're almost there; the Mozilla interface is largely CSS+JavaScript (with XUL in there somewhere), and recent versions of Windows Explorer are HTML+CSS+JScript...)
If you look at Display Postscript, and try to replace bits and pieces with SVG, here's what you need:
That doesn't sound too far off. And it has some advantages over Display Postscript, not the least of which is that hacking in FORTH isn't as desirable as making GUI widgets declaratively (in text).
