Michael,

Well, given those two possibilities, I guess I would personally favor Webkit, mainly because all of the tool frameworks I've been building for the last several years all work with Qt (or wxWindows) :-)

If you remember some of the screen shots I posted a while back, the UIs were all created using the tool set I've been developing, running on top of Qt. If you go that route, hopefully you'll also open up the scripting interface to use other languages, such as Python. Since your low-level API is COM-based, that should be fairly easy to do, since Python already has pretty good support for COM I've heard.

Just FYI, the new Lightwave CORE system is Qt-based and supports Python scripting. I've had no problems integrating my framework into CORE to produce new UI's in the few experiments I've tried so far...